diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
index 7908617..0296b44 100644
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -14,7 +14,15 @@
       <option name="DECONSTRUCTION_LIST_WRAP" value="5" />
       <option name="MULTI_CATCH_TYPES_WRAP" value="0" />
     </JavaCodeStyleSettings>
+    <TypeScriptCodeStyleSettings version="0">
+      <option name="SPACES_WITHIN_OBJECT_LITERAL_BRACES" value="true" />
+      <option name="SPACES_WITHIN_IMPORTS" value="true" />
+    </TypeScriptCodeStyleSettings>
     <codeStyleSettings language="JAVA">
+      <option name="KEEP_BLANK_LINES_IN_DECLARATIONS" value="1" />
+      <option name="KEEP_BLANK_LINES_IN_CODE" value="1" />
+      <option name="KEEP_BLANK_LINES_BETWEEN_PACKAGE_DECLARATION_AND_HEADER" value="1" />
+      <option name="KEEP_BLANK_LINES_BEFORE_RBRACE" value="0" />
       <option name="ALIGN_MULTILINE_PARAMETERS_IN_CALLS" value="true" />
       <option name="ALIGN_MULTILINE_ARRAY_INITIALIZER_EXPRESSION" value="true" />
       <option name="CALL_PARAMETERS_WRAP" value="5" />
@@ -30,6 +38,10 @@
       <option name="ARRAY_INITIALIZER_WRAP" value="5" />
       <option name="ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE" value="true" />
       <option name="ARRAY_INITIALIZER_RBRACE_ON_NEXT_LINE" value="true" />
+      <option name="IF_BRACE_FORCE" value="3" />
+      <option name="DOWHILE_BRACE_FORCE" value="3" />
+      <option name="WHILE_BRACE_FORCE" value="3" />
+      <option name="FOR_BRACE_FORCE" value="3" />
       <option name="KEEP_BUILDER_METHODS_INDENTS" value="true" />
     </codeStyleSettings>
   </code_scheme>
diff --git a/lombok.config b/lombok.config
new file mode 100644
index 0000000..5ffcbcb
--- /dev/null
+++ b/lombok.config
@@ -0,0 +1,9 @@
+config.stopBubbling = true
+
+# Required for NullAway to work
+lombok.addLombokGeneratedAnnotation = true
+
+# Copy JSpecify annotations to generated code (constructors, getters, setters)
+lombok.copyableAnnotations += org.jspecify.annotations.Nullable
+lombok.copyableAnnotations += org.jspecify.annotations.NonNull
+lombok.addNullAnnotations = jspecify
diff --git a/pom.xml b/pom.xml
index d4b27b4..1f75985 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1,11 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>4.0.0</version>
+        <version>4.0.1</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
@@ -17,8 +18,20 @@
 
     <properties>
         <java.version>25</java.version>
+        <errorprone.version>2.45.0</errorprone.version>
+        <nullaway.version>0.12.14</nullaway.version>
     </properties>
 
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>it.aboutbits</groupId>
+                <artifactId>archunit-toolbox</artifactId>
+                <version>1.0.0-RC1</version>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
@@ -135,6 +148,26 @@
             <version>2.0.2</version>
             <scope>test</scope>
         </dependency>
+
+        <!-- https://mvnrepository.com/artifact/com.tngtech.archunit/archunit-junit5 -->
+        <dependency>
+            <groupId>com.tngtech.archunit</groupId>
+            <artifactId>archunit-junit5</artifactId>
+            <version>1.4.1</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.tngtech.archunit</groupId>
+            <artifactId>archunit-junit5-api</artifactId>
+            <version>1.4.1</version>
+            <scope>compile</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>it.aboutbits</groupId>
+            <artifactId>archunit-toolbox</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -156,7 +189,36 @@
                             <artifactId>lombok</artifactId>
                             <version>${lombok.version}</version>
                         </path>
+                        <path>
+                            <groupId>com.google.errorprone</groupId>
+                            <artifactId>error_prone_core</artifactId>
+                            <version>${errorprone.version}</version>
+                        </path>
+                        <path>
+                            <groupId>com.uber.nullaway</groupId>
+                            <artifactId>nullaway</artifactId>
+                            <version>${nullaway.version}</version>
+                        </path>
                     </annotationProcessorPaths>
+                    <compilerArgs>
+                        <arg>-Amapstruct.unmappedTargetPolicy=ERROR</arg>
+                        <arg>-XDcompilePolicy=simple</arg>
+                        <arg>--should-stop=ifError=FLOW</arg>
+                        <!-- @formatter:off -->
+                        <arg>-Xplugin:ErrorProne -XepDisableAllChecks -XepOpt:NullAway:AnnotatedPackages=it.aboutbits.springboot.toolbox -XepOpt:NullAway:JSpecifyMode=true -Xep:NullAway:ERROR -XepOpt:NullAway:ExcludedFieldAnnotations=org.mockito.InjectMocks,org.mockito.Mock</arg>
+                        <!-- @formatter:on -->
+                        <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED</arg>
+                        <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED</arg>
+                        <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED</arg>
+                        <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED</arg>
+                        <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED</arg>
+                        <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED</arg>
+                        <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED</arg>
+                        <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED</arg>
+                        <arg>-J--add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED</arg>
+                        <arg>-J--add-opens=jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED</arg>
+                    </compilerArgs>
+                    <fork>true</fork>
                 </configuration>
             </plugin>
             <plugin>
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/AbstractCustomTypeContributor.java b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/AbstractCustomTypeContributor.java
index 3f0f02e..98e7473 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/AbstractCustomTypeContributor.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/AbstractCustomTypeContributor.java
@@ -6,10 +6,12 @@
 import org.hibernate.boot.model.TypeContributor;
 import org.hibernate.service.ServiceRegistry;
 import org.hibernate.type.descriptor.java.JavaType;
+import org.jspecify.annotations.NullMarked;
 
 import java.lang.reflect.InvocationTargetException;
 import java.util.Set;
 
+@NullMarked
 public abstract class AbstractCustomTypeContributor implements TypeContributor {
     @SuppressWarnings("rawtypes")
     private final Set<Class<? extends AutoRegisteredJavaType>> relevantTypes;
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/AutoRegisteredJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/AutoRegisteredJavaType.java
index 881a05b..09b5a7c 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/AutoRegisteredJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/AutoRegisteredJavaType.java
@@ -1,6 +1,8 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.persistence;
 
 import org.hibernate.type.descriptor.java.JavaType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public interface AutoRegisteredJavaType<T> extends JavaType<T> {
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/CustomTypeContributor.java b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/CustomTypeContributor.java
index 8bd8407..3faa4b1 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/CustomTypeContributor.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/CustomTypeContributor.java
@@ -1,5 +1,8 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.persistence;
 
+import org.jspecify.annotations.NullMarked;
+
+@NullMarked
 public final class CustomTypeContributor extends AbstractCustomTypeContributor {
     public CustomTypeContributor() {
         super("it.aboutbits.springboot.toolbox");
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeConfiguration.java b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeConfiguration.java
index eeaadfd..d133ced 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeConfiguration.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeConfiguration.java
@@ -7,6 +7,7 @@
 import it.aboutbits.springboot.toolbox.type.identity.EntityId;
 import it.aboutbits.springboot.toolbox.web.CustomTypePropertyEditor;
 import it.aboutbits.springboot.toolbox.web.EntityIdPropertyEditor;
+import org.jspecify.annotations.NullMarked;
 import org.springframework.boot.jackson.autoconfigure.JsonMapperBuilderCustomizer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -18,6 +19,7 @@
 import java.util.Set;
 
 @Configuration
+@NullMarked
 public class CustomTypeConfiguration {
     @ControllerAdvice
     public static class CustomTypePropertyBinder {
@@ -46,8 +48,8 @@ public JsonMapperBuilderCustomizer jsonCustomizer(CustomTypeScanner configuratio
 
         // dynamic deserializers
         configuration.getRelevantTypes()
-                .forEach(type ->
-                                 module.addDeserializer(type, new CustomTypeDeserializer(type))
+                .forEach(
+                        type -> module.addDeserializer(type, new CustomTypeDeserializer(type))
                 );
 
         // type-based deserializer
@@ -56,5 +58,4 @@ public JsonMapperBuilderCustomizer jsonCustomizer(CustomTypeScanner configuratio
         return builder -> builder
                 .addModule(module);
     }
-
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeScanner.java b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeScanner.java
index f374c31..36242c9 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeScanner.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeScanner.java
@@ -4,6 +4,7 @@
 import it.aboutbits.springboot.toolbox.type.CustomType;
 import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.NullMarked;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
@@ -18,6 +19,7 @@
 
 @Slf4j
 @Getter
+@NullMarked
 public class CustomTypeScanner {
     private static final String LIBRARY_BASE_PACKAGE_NAME = "it.aboutbits.springboot.toolbox";
 
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeScannerRegistrar.java b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeScannerRegistrar.java
index a77f0b7..56535da 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeScannerRegistrar.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/CustomTypeScannerRegistrar.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.web;
 
+import org.jspecify.annotations.NullMarked;
 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
@@ -8,6 +9,7 @@
 
 import java.util.Objects;
 
+@NullMarked
 public class CustomTypeScannerRegistrar implements ImportBeanDefinitionRegistrar {
 
     /**
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/RegisterCustomTypesWithJacksonAndMvc.java b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/RegisterCustomTypesWithJacksonAndMvc.java
index c4d6ffe..8af1f3c 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/RegisterCustomTypesWithJacksonAndMvc.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/autoconfiguration/web/RegisterCustomTypesWithJacksonAndMvc.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.web;
 
+import org.jspecify.annotations.NullMarked;
 import org.springframework.context.annotation.Import;
 
 import java.lang.annotation.ElementType;
@@ -10,6 +11,7 @@
 @Target({ElementType.TYPE})
 @Retention(RetentionPolicy.RUNTIME)
 @Import({CustomTypeScannerRegistrar.class, CustomTypeConfiguration.class})
+@NullMarked
 public @interface RegisterCustomTypesWithJacksonAndMvc {
     String[] additionalTypePackages() default "";
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/exception/ClientRuntimeException.java b/src/main/java/it/aboutbits/springboot/toolbox/exception/ClientRuntimeException.java
index 156afcf..303fcd9 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/exception/ClientRuntimeException.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/exception/ClientRuntimeException.java
@@ -1,5 +1,8 @@
 package it.aboutbits.springboot.toolbox.exception;
 
+import org.jspecify.annotations.NullMarked;
+
+@NullMarked
 public class ClientRuntimeException extends RuntimeException {
     public ClientRuntimeException() {
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/exception/ConstraintViolationExceptionBuilder.java b/src/main/java/it/aboutbits/springboot/toolbox/exception/ConstraintViolationExceptionBuilder.java
index 5caf125..22c2cc9 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/exception/ConstraintViolationExceptionBuilder.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/exception/ConstraintViolationExceptionBuilder.java
@@ -4,71 +4,82 @@
 import jakarta.validation.ConstraintViolationException;
 import jakarta.validation.Path;
 import jakarta.validation.metadata.ConstraintDescriptor;
-import lombok.NonNull;
 import org.hibernate.validator.internal.engine.path.PathImpl;
-import org.springframework.lang.Nullable;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.util.HashSet;
 import java.util.Set;
 
+@NullMarked
 public final class ConstraintViolationExceptionBuilder {
     private final Set<ConstraintViolation<?>> constraintViolations = new HashSet<>();
 
     private ConstraintViolationExceptionBuilder() {
-
     }
 
+    @SuppressWarnings("unused")
     public static ConstraintViolationExceptionBuilder constraintViolation() {
         return new ConstraintViolationExceptionBuilder();
     }
 
+    @SuppressWarnings("unused")
     public ConstraintViolationExceptionBuilder causedBy(
-            @NonNull String propertyPath,
-            @NonNull ExceptionMessageDefinition message
+            String propertyPath,
+            ExceptionMessageDefinition message
     ) {
         return causedBy(propertyPath, message.code());
     }
 
-    public ConstraintViolationExceptionBuilder causedBy(@NonNull String propertyPath, @Nullable String message) {
+    @SuppressWarnings({"unused", "UnusedReturnValue"})
+    public ConstraintViolationExceptionBuilder causedBy(String propertyPath, String message) {
         var constraintViolation = new CustomConstraintViolation(message, PathImpl.createPathFromString(propertyPath));
         constraintViolations.add(constraintViolation);
         return this;
     }
 
-    public ConstraintViolationExceptionBuilder causedBy(@NonNull ConstraintViolationException e) {
+    @SuppressWarnings({"unused", "UnusedReturnValue"})
+    public ConstraintViolationExceptionBuilder causedBy(ConstraintViolationException e) {
         constraintViolations.addAll(e.getConstraintViolations());
         return this;
     }
 
+    @SuppressWarnings("unused")
     public ConstraintViolationException create() {
         return new ConstraintViolationException(constraintViolations);
     }
 
+    @SuppressWarnings("unused")
     public boolean hasCauses() {
         return !constraintViolations.isEmpty();
     }
 
-    private record CustomConstraintViolation(String message, Path propertyPath) implements ConstraintViolation<Object> {
+    @NullMarked
+    public record CustomConstraintViolation(String message, Path propertyPath) implements ConstraintViolation<Object> {
         @Override
         public String getMessage() {
             return message;
         }
 
+        @Nullable
         @Override
         public String getMessageTemplate() {
             return null;
         }
 
+        @Nullable
         @Override
         public Object getRootBean() {
             return null;
         }
 
+        @Nullable
         @Override
         public Class<Object> getRootBeanClass() {
             return null;
         }
 
+        @Nullable
         @Override
         public Object getLeafBean() {
             return null;
@@ -79,6 +90,7 @@ public Object[] getExecutableParameters() {
             return new Object[0];
         }
 
+        @Nullable
         @Override
         public Object getExecutableReturnValue() {
             return null;
@@ -89,16 +101,19 @@ public Path getPropertyPath() {
             return propertyPath;
         }
 
+        @Nullable
         @Override
         public Object getInvalidValue() {
             return null;
         }
 
+        @Nullable
         @Override
         public ConstraintDescriptor<?> getConstraintDescriptor() {
             return null;
         }
 
+        @Nullable
         @Override
         public <U> U unwrap(Class<U> type) {
             return null;
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/exception/ExceptionMessageDefinition.java b/src/main/java/it/aboutbits/springboot/toolbox/exception/ExceptionMessageDefinition.java
index 5c6da3f..cacc290 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/exception/ExceptionMessageDefinition.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/exception/ExceptionMessageDefinition.java
@@ -1,5 +1,7 @@
 package it.aboutbits.springboot.toolbox.exception;
 
+import org.jspecify.annotations.NullMarked;
+
 /**
  * Use this to create a class or enum that defines the exception messages.
  * This way, the messages can be referenced by a constant rather than using plain strings.
@@ -16,6 +18,7 @@
  * }
  *}
  */
+@NullMarked
 public interface ExceptionMessageDefinition {
     String code();
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/exception/ServerRuntimeException.java b/src/main/java/it/aboutbits/springboot/toolbox/exception/ServerRuntimeException.java
index 0a20748..62f175c 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/exception/ServerRuntimeException.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/exception/ServerRuntimeException.java
@@ -1,5 +1,8 @@
 package it.aboutbits.springboot.toolbox.exception;
 
+import org.jspecify.annotations.NullMarked;
+
+@NullMarked
 public class ServerRuntimeException extends RuntimeException {
     public ServerRuntimeException() {
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/jackson/CustomTypeDeserializer.java b/src/main/java/it/aboutbits/springboot/toolbox/jackson/CustomTypeDeserializer.java
index 56ee436..877447e 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/jackson/CustomTypeDeserializer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/jackson/CustomTypeDeserializer.java
@@ -3,6 +3,8 @@
 import it.aboutbits.springboot.toolbox.reflection.util.CustomTypeReflectionUtil;
 import it.aboutbits.springboot.toolbox.type.CustomType;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import tools.jackson.core.JacksonException;
 import tools.jackson.core.JsonParser;
 import tools.jackson.core.TokenStreamLocation;
@@ -18,10 +20,11 @@
 import java.util.UUID;
 import java.util.function.Function;
 
+@NullMarked
 public class CustomTypeDeserializer<T extends CustomType<?>> extends ValueDeserializer<T> {
     private final Class<T> customType;
     private final Constructor<T> constructor;
-    private final Function<JsonParser, Object> typeConverter;
+    private final Function<JsonParser, @Nullable Object> typeConverter;
 
     public CustomTypeDeserializer(Class<T> customType) {
         this.customType = customType;
@@ -98,7 +101,7 @@ protected Ex(Closeable processor, String msg, TokenStreamLocation loc) {
         }
     }
 
-    private static Function<JsonParser, Object> getTypeConverter(Class<?> wrappedType) {
+    private static Function<JsonParser, @Nullable Object> getTypeConverter(Class<?> wrappedType) {
         if (Byte.class.isAssignableFrom(wrappedType)) {
             return getByteConverter();
         }
@@ -144,7 +147,7 @@ private static Function<JsonParser, Object> getTypeConverter(Class<?> wrappedTyp
         throw new CustomTypeDeserializerException("Value type not supported: " + wrappedType.getName());
     }
 
-    private static Function<JsonParser, Object> getByteConverter() {
+    private static Function<JsonParser, @Nullable Object> getByteConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getByteValue();
@@ -154,7 +157,7 @@ private static Function<JsonParser, Object> getByteConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getBooleanConverter() {
+    private static Function<JsonParser, @Nullable Object> getBooleanConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getBooleanValue();
@@ -164,7 +167,7 @@ private static Function<JsonParser, Object> getBooleanConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getScaledBigDecimalConverter() {
+    private static Function<JsonParser, @Nullable Object> getScaledBigDecimalConverter() {
         return jsonParser -> {
             try {
                 return new ScaledBigDecimal(jsonParser.getDecimalValue());
@@ -174,7 +177,7 @@ private static Function<JsonParser, Object> getScaledBigDecimalConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getBigDecimalConverter() {
+    private static Function<JsonParser, @Nullable Object> getBigDecimalConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getDecimalValue();
@@ -184,7 +187,7 @@ private static Function<JsonParser, Object> getBigDecimalConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getDoubleConverter() {
+    private static Function<JsonParser, @Nullable Object> getDoubleConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getDoubleValue();
@@ -194,7 +197,7 @@ private static Function<JsonParser, Object> getDoubleConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getFloatConverter() {
+    private static Function<JsonParser, @Nullable Object> getFloatConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getFloatValue();
@@ -204,7 +207,7 @@ private static Function<JsonParser, Object> getFloatConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getBigIntegerConverter() {
+    private static Function<JsonParser, @Nullable Object> getBigIntegerConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getBigIntegerValue();
@@ -214,7 +217,7 @@ private static Function<JsonParser, Object> getBigIntegerConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getLongConverter() {
+    private static Function<JsonParser, @Nullable Object> getLongConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getLongValue();
@@ -224,7 +227,7 @@ private static Function<JsonParser, Object> getLongConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getIntegerConverter() {
+    private static Function<JsonParser, @Nullable Object> getIntegerConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getIntValue();
@@ -234,7 +237,7 @@ private static Function<JsonParser, Object> getIntegerConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getShortConverter() {
+    private static Function<JsonParser, @Nullable Object> getShortConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getShortValue();
@@ -244,7 +247,7 @@ private static Function<JsonParser, Object> getShortConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getStringConverter() {
+    private static Function<JsonParser, @Nullable Object> getStringConverter() {
         return jsonParser -> {
             try {
                 return jsonParser.getValueAsString();
@@ -254,7 +257,7 @@ private static Function<JsonParser, Object> getStringConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getCharConverter() {
+    private static Function<JsonParser, @Nullable Object> getCharConverter() {
         return jsonParser -> {
             try {
                 var value = jsonParser.getValueAsString();
@@ -273,7 +276,7 @@ private static Function<JsonParser, Object> getCharConverter() {
         };
     }
 
-    private static Function<JsonParser, Object> getUUIDConverter() {
+    private static Function<JsonParser, @Nullable Object> getUUIDConverter() {
         return jsonParser -> {
             try {
                 var value = jsonParser.getValueAsString();
@@ -293,7 +296,7 @@ private static Function<JsonParser, Object> getUUIDConverter() {
     }
 
     @SuppressWarnings("unchecked")
-    private static Function<JsonParser, Object> getEnumConverter(Class<?> wrappedType) {
+    private static Function<JsonParser, @Nullable Object> getEnumConverter(Class<?> wrappedType) {
         var enumClass = (Class<? extends Enum<?>>) wrappedType.asSubclass(Enum.class);
         return jsonParser -> {
             try {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/jackson/CustomTypeSerializer.java b/src/main/java/it/aboutbits/springboot/toolbox/jackson/CustomTypeSerializer.java
index 1e97a8a..86067d6 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/jackson/CustomTypeSerializer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/jackson/CustomTypeSerializer.java
@@ -1,13 +1,14 @@
 package it.aboutbits.springboot.toolbox.jackson;
 
-
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 import tools.jackson.core.JsonGenerator;
 import tools.jackson.databind.SerializationContext;
 import tools.jackson.databind.ValueSerializer;
 
 import java.util.UUID;
 
+@NullMarked
 public class CustomTypeSerializer extends ValueSerializer<CustomType<?>> {
     @SuppressWarnings("unchecked")
     @Override
@@ -27,7 +28,6 @@ public void serialize(
             case String stringValue -> jsonGenerator.writeString(stringValue);
             case UUID uuidValue -> jsonGenerator.writeString(uuidValue.toString());
             case Enum<?> enumValue -> jsonGenerator.writeString(enumValue.name());
-            case null -> jsonGenerator.writeNull();
             default -> jsonGenerator.writeRawValue(String.valueOf(value));
         }
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/jackson/EntityIdDeserializer.java b/src/main/java/it/aboutbits/springboot/toolbox/jackson/EntityIdDeserializer.java
index 04029bc..60d60a3 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/jackson/EntityIdDeserializer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/jackson/EntityIdDeserializer.java
@@ -1,11 +1,13 @@
 package it.aboutbits.springboot.toolbox.jackson;
 
 import it.aboutbits.springboot.toolbox.type.identity.EntityId;
+import org.jspecify.annotations.NullMarked;
 import tools.jackson.core.JsonParser;
 import tools.jackson.core.exc.InputCoercionException;
 import tools.jackson.databind.DeserializationContext;
 import tools.jackson.databind.ValueDeserializer;
 
+@NullMarked
 public class EntityIdDeserializer extends ValueDeserializer<EntityId<?>> {
     /*
     This is needed because EntityId is just the interface. Jackson does not know what implementation to take.
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/parameter/PageParameter.java b/src/main/java/it/aboutbits/springboot/toolbox/parameter/PageParameter.java
index ff326bf..af21d88 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/parameter/PageParameter.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/parameter/PageParameter.java
@@ -5,12 +5,15 @@
 import lombok.ToString;
 import lombok.experimental.Accessors;
 import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Sort;
 
 @Slf4j
 @ToString
 @Accessors(fluent = true)
+@NullMarked
 public final class PageParameter {
     @Getter
     @Setter
@@ -27,7 +30,7 @@ private record PageInfo(int page, int size, boolean paged) {
 
     private final PageInfo pageInfo;
 
-    private PageParameter(Integer page, Integer size) {
+    private PageParameter(@Nullable Integer page, @Nullable Integer size) {
         var actualPage = (page == null) ? 0 : page;
         var actualSize = (size == null) ? DEFAULT_PAGE_SIZE : size;
 
@@ -46,11 +49,11 @@ private PageParameter() {
         pageInfo = new PageInfo(0, Integer.MAX_VALUE, false);
     }
 
-    public static PageParameter of(Integer page) {
+    public static PageParameter of(@Nullable Integer page) {
         return new PageParameter(page, null);
     }
 
-    public static PageParameter of(Integer page, Integer size) {
+    public static PageParameter of(@Nullable Integer page, @Nullable Integer size) {
         return new PageParameter(page, size);
     }
 
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/parameter/SortParameter.java b/src/main/java/it/aboutbits/springboot/toolbox/parameter/SortParameter.java
index 12ae84e..8872cf4 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/parameter/SortParameter.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/parameter/SortParameter.java
@@ -2,13 +2,15 @@
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
-import lombok.NonNull;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.domain.Sort;
 
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -19,6 +21,7 @@
  * with various configurations, including direction and null-handling behavior.
  */
 @EqualsAndHashCode
+@NullMarked
 public final class SortParameter<T extends Enum<?> & SortParameter.Definition> {
     private static final String DEFAULT_SORT_PROPERTY = "id";
     private static final Sort.Direction DEFAULT_SORT_DIRETION = Sort.Direction.ASC;
@@ -27,7 +30,7 @@ public final class SortParameter<T extends Enum<?> & SortParameter.Definition> {
     @Getter
     private final List<SortField> sortFields = new ArrayList<>();
 
-    public SortParameter(List<SortField> sortFields) {
+    public SortParameter(@Nullable List<SortField> sortFields) {
         if (sortFields == null) {
             return;
         }
@@ -59,7 +62,7 @@ public static <T extends Enum<?> & Definition> SortParameter<T> unsorted() {
      */
     @SafeVarargs
     public static <T extends Enum<?> & Definition> SortParameter<T> by(
-            @NonNull T... sortDefinitions
+            T... sortDefinitions
     ) {
         return new SortParameter<>(
                 Stream.of(sortDefinitions)
@@ -85,8 +88,8 @@ public static <T extends Enum<?> & Definition> SortParameter<T> by(
      * @return an instance of {@link SortParameter} configured with the given sort definition and direction.
      */
     public static <T extends Enum<?> & Definition> SortParameter<T> by(
-            @NonNull T sortDefinition,
-            @NonNull Sort.Direction direction
+            T sortDefinition,
+            Sort.Direction direction
     ) {
         return new SortParameter<>(
                 List.of(new SortField(
@@ -110,9 +113,9 @@ public static <T extends Enum<?> & Definition> SortParameter<T> by(
      * @return an instance of {@link SortParameter} configured with the given sort definition, direction, and null-handling behavior.
      */
     public static <T extends Enum<?> & Definition> SortParameter<T> by(
-            @NonNull T sortDefinition,
-            @NonNull Sort.Direction direction,
-            @NonNull Sort.NullHandling nullHandling
+            T sortDefinition,
+            Sort.Direction direction,
+            Sort.NullHandling nullHandling
     ) {
         return new SortParameter<>(
                 List.of(new SortField(
@@ -134,7 +137,7 @@ public static <T extends Enum<?> & Definition> SortParameter<T> by(
      */
     @SafeVarargs
     public final SortParameter<T> and(
-            @NonNull T... sortDefinitions
+            T... sortDefinitions
     ) {
         sortFields.addAll(
                 Stream.of(sortDefinitions)
@@ -160,8 +163,8 @@ public final SortParameter<T> and(
      * @return the updated {@link SortParameter} instance containing the new sorting criterion.
      */
     public SortParameter<T> and(
-            @NonNull T sortDefinition,
-            @NonNull Sort.Direction direction
+            T sortDefinition,
+            Sort.Direction direction
     ) {
         sortFields.add(
                 new SortField(
@@ -185,9 +188,9 @@ public SortParameter<T> and(
      * @return the updated {@link SortParameter} instance containing the new sorting criterion.
      */
     public SortParameter<T> and(
-            @NonNull T sortDefinition,
-            @NonNull Sort.Direction direction,
-            @NonNull Sort.NullHandling nullHandling
+            T sortDefinition,
+            Sort.Direction direction,
+            Sort.NullHandling nullHandling
     ) {
         sortFields.add(
                 new SortField(
@@ -209,7 +212,7 @@ public SortParameter<T> and(
      * @return the current {@link SortParameter} if it has defined sorting fields,
      * or the provided fallback if it does not.
      */
-    public SortParameter<T> or(@NonNull SortParameter<T> fallback) {
+    public SortParameter<T> or(SortParameter<T> fallback) {
         return sortFields.isEmpty() ? fallback : this;
     }
 
@@ -223,7 +226,7 @@ public SortParameter<T> or(@NonNull SortParameter<T> fallback) {
      * @return an instance of {@link Sort} created using the transformed key-value mapping,
      * excluding default sorting behavior.
      */
-    public Sort buildSortWithoutDefault(@NonNull Map<T, String> mapping) {
+    public Sort buildSortWithoutDefault(Map<T, String> mapping) {
         var stringMapping = mapping.entrySet().stream()
                 .collect(Collectors.toMap(
                         entry -> entry.getKey().name(),
@@ -243,7 +246,7 @@ public Sort buildSortWithoutDefault(@NonNull Map<T, String> mapping) {
      *                The enumeration keys must implement the `name()` method to retrieve their string representation.
      * @return an instance of {@link Sort} created using the transformed key-value mapping with default sorting behavior.
      */
-    public Sort buildSort(@NonNull Map<T, String> mapping) {
+    public Sort buildSort(Map<T, String> mapping) {
         var stringMapping = mapping.entrySet().stream()
                 .collect(Collectors.toMap(
                         entry -> entry.getKey().name(),
@@ -253,7 +256,7 @@ public Sort buildSort(@NonNull Map<T, String> mapping) {
         return buildSort(stringMapping, true);
     }
 
-    private Sort buildSort(@NonNull Map<String, String> mapping, boolean withDefault) {
+    private Sort buildSort(Map<String, String> mapping, boolean withDefault) {
         if (sortFields.isEmpty()) {
             return withDefault ? getMappedDefaultSort(mapping) : Sort.unsorted();
         }
@@ -261,12 +264,17 @@ private Sort buildSort(@NonNull Map<String, String> mapping, boolean withDefault
         var additionalSort = Sort.by(
                 new ArrayList<>(
                         sortFields.stream()
-                                .filter(sortField -> mapping.containsKey(sortField.property()))
-                                .map(sortField -> new Sort.Order(
-                                        sortField.direction(),
-                                        mapping.get(sortField.property()),
-                                        sortField.nullHandling()
-                                ))
+                                .map(sortField -> {
+                                    if (!mapping.containsKey(sortField.property())) {
+                                        return null;
+                                    }
+                                    return new Sort.Order(
+                                            sortField.direction(),
+                                            mapping.get(sortField.property()),
+                                            sortField.nullHandling()
+                                    );
+                                })
+                                .filter(Objects::nonNull)
                                 .toList()
                 )
         );
@@ -285,9 +293,9 @@ private static Sort getMappedDefaultSort(Map<String, String> mapping) {
     }
 
     public record SortField(
-            @NonNull String property,
-            @NonNull Sort.Direction direction,
-            @NonNull Sort.NullHandling nullHandling
+            String property,
+            Sort.Direction direction,
+            Sort.NullHandling nullHandling
     ) {
     }
 
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/ChangeAware.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/ChangeAware.java
index b1c0339..e90943e 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/ChangeAware.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/ChangeAware.java
@@ -1,7 +1,10 @@
 package it.aboutbits.springboot.toolbox.persistence;
 
+import org.jspecify.annotations.NullMarked;
+
 import java.time.OffsetDateTime;
 
+@NullMarked
 public interface ChangeAware {
     OffsetDateTime getCreatedAt();
 
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/SortMappings.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/SortMappings.java
index ba59fda..f8615e8 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/SortMappings.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/SortMappings.java
@@ -1,25 +1,26 @@
 package it.aboutbits.springboot.toolbox.persistence;
 
 import it.aboutbits.springboot.toolbox.parameter.SortParameter;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 
 import java.util.HashMap;
 
+@NullMarked
 public final class SortMappings<T extends Enum<?> & SortParameter.Definition> extends HashMap<T, String> {
     private SortMappings() {
         super();
     }
 
     public static <T extends Enum<?> & SortParameter.Definition> Mapping<T> map(
-            @NonNull T property,
-            @NonNull String column
+            T property,
+            String column
     ) {
         return new Mapping<>(property, column);
     }
 
     @SafeVarargs
     public static <T extends Enum<?> & SortParameter.Definition> SortMappings<T> of(
-            @NonNull Mapping<T>... mappings
+            Mapping<T>... mappings
     ) {
         var sortMappings = new SortMappings<T>();
 
@@ -30,6 +31,6 @@ public static <T extends Enum<?> & SortParameter.Definition> SortMappings<T> of(
         return sortMappings;
     }
 
-    public record Mapping<T extends Enum<?> & SortParameter.Definition>(@NonNull T property, @NonNull String column) {
+    public record Mapping<T extends Enum<?> & SortParameter.Definition>(T property, String column) {
     }
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/converter/UUIDConverter.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/converter/UUIDConverter.java
index 1ccbdd1..cef38ba 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/converter/UUIDConverter.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/converter/UUIDConverter.java
@@ -2,13 +2,17 @@
 
 import jakarta.persistence.AttributeConverter;
 import jakarta.persistence.Converter;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.util.UUID;
 
 @Converter
+@NullMarked
 public class UUIDConverter implements AttributeConverter<UUID, String> {
     @Override
-    public String convertToDatabaseColumn(UUID attribute) {
+    @Nullable
+    public String convertToDatabaseColumn(@Nullable UUID attribute) {
         if (attribute == null) {
             return null;
         }
@@ -17,7 +21,8 @@ public String convertToDatabaseColumn(UUID attribute) {
     }
 
     @Override
-    public UUID convertToEntityAttribute(String dbData) {
+    @Nullable
+    public UUID convertToEntityAttribute(@Nullable String dbData) {
         if (dbData == null || dbData.isBlank()) {
             return null;
         }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/EmailAddressJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/EmailAddressJavaType.java
index 4ee5961..8f824ec 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/EmailAddressJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/EmailAddressJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedStringJavaType;
 import it.aboutbits.springboot.toolbox.type.EmailAddress;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class EmailAddressJavaType extends WrappedStringJavaType<EmailAddress> implements AutoRegisteredJavaType<EmailAddress> {
     public EmailAddressJavaType() {
         super(EmailAddress.class);
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/IbanJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/IbanJavaType.java
index 020c787..7e2d63b 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/IbanJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/IbanJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedStringJavaType;
 import it.aboutbits.springboot.toolbox.type.Iban;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class IbanJavaType extends WrappedStringJavaType<Iban> implements AutoRegisteredJavaType<Iban> {
     public IbanJavaType() {
         super(Iban.class);
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/ScaledBigDecimalJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/ScaledBigDecimalJavaType.java
index 7b659db..e2825b0 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/ScaledBigDecimalJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/ScaledBigDecimalJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedBigDecimalJavaType;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class ScaledBigDecimalJavaType extends WrappedBigDecimalJavaType<ScaledBigDecimal> implements AutoRegisteredJavaType<ScaledBigDecimal> {
     public ScaledBigDecimalJavaType() {
         super(ScaledBigDecimal.class);
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBigDecimalJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBigDecimalJavaType.java
index 01e5415..615222b 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBigDecimalJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBigDecimalJavaType.java
@@ -6,12 +6,15 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.math.BigDecimal;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedBigDecimalJavaType<T extends CustomType<BigDecimal>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -34,7 +37,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -53,7 +57,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBigIntegerJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBigIntegerJavaType.java
index e22a8fb..17be08e 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBigIntegerJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBigIntegerJavaType.java
@@ -6,12 +6,15 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.math.BigInteger;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedBigIntegerJavaType<T extends CustomType<BigInteger>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -34,7 +37,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -53,7 +57,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBooleanJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBooleanJavaType.java
index 8ccc5c8..33b6137 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBooleanJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedBooleanJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedBooleanJavaType<T extends CustomType<Boolean>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -33,7 +36,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -52,7 +56,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedByteJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedByteJavaType.java
index 300c4ed..21135b1 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedByteJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedByteJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedByteJavaType<T extends CustomType<Byte>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -33,7 +36,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -52,7 +56,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedCharacterJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedCharacterJavaType.java
index 7400993..08d0734 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedCharacterJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedCharacterJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedCharacterJavaType<T extends CustomType<Character>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -33,7 +36,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -55,7 +59,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedDoubleJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedDoubleJavaType.java
index de8becf..726a330 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedDoubleJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedDoubleJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedDoubleJavaType<T extends CustomType<Double>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -33,7 +36,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -52,7 +56,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedEnumJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedEnumJavaType.java
index 3377506..20aad77 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedEnumJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedEnumJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedEnumJavaType<T extends CustomType<? extends Enum<?>>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
     private final Class<? extends Enum<?>> enumClass;
@@ -58,7 +61,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -80,7 +84,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedFloatJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedFloatJavaType.java
index 271daae..834429e 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedFloatJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedFloatJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedFloatJavaType<T extends CustomType<Float>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -33,7 +36,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -52,7 +56,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedIntegerJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedIntegerJavaType.java
index 8a97853..759ca75 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedIntegerJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedIntegerJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedIntegerJavaType<T extends CustomType<Integer>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -33,7 +36,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -52,7 +56,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedLongJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedLongJavaType.java
index eadaddb..73a298f 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedLongJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedLongJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedLongJavaType<T extends CustomType<Long>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -33,7 +36,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -52,7 +56,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedScaledBigDecimalJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedScaledBigDecimalJavaType.java
index db7cd1a..0cee766 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedScaledBigDecimalJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedScaledBigDecimalJavaType.java
@@ -7,11 +7,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedScaledBigDecimalJavaType<T extends CustomType<ScaledBigDecimal>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -34,7 +37,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -53,7 +57,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedShortJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedShortJavaType.java
index 3dac3f0..e73c689 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedShortJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedShortJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedShortJavaType<T extends CustomType<Short>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -33,7 +36,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -52,7 +56,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedStringJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedStringJavaType.java
index fcd7a46..d6abfba 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedStringJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedStringJavaType.java
@@ -6,11 +6,14 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.Types;
 
+@NullMarked
 public abstract class WrappedStringJavaType<T extends CustomType<String>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -33,7 +36,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -52,7 +56,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedUUIDJavaType.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedUUIDJavaType.java
index af9eddc..f89b6bb 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedUUIDJavaType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/javatype/base/WrappedUUIDJavaType.java
@@ -6,6 +6,8 @@
 import org.hibernate.type.descriptor.java.AbstractClassJavaType;
 import org.hibernate.type.descriptor.jdbc.JdbcType;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
@@ -13,6 +15,7 @@
 import java.sql.Types;
 import java.util.UUID;
 
+@NullMarked
 public abstract class WrappedUUIDJavaType<T extends CustomType<UUID>> extends AbstractClassJavaType<T> {
     private final transient Constructor<T> constructor;
 
@@ -35,7 +38,8 @@ public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
 
     @SuppressWarnings("unchecked")
     @Override
-    public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> X unwrap(@Nullable T id, Class<X> aClass, WrapperOptions wrapperOptions) {
         var javaTypeClass = getJavaTypeClass();
 
         if (id == null) {
@@ -60,7 +64,8 @@ public <X> X unwrap(T id, Class<X> aClass, WrapperOptions wrapperOptions) {
     @SuppressWarnings("unchecked")
     @SneakyThrows({InstantiationException.class, IllegalAccessException.class, InvocationTargetException.class})
     @Override
-    public <X> T wrap(X value, WrapperOptions wrapperOptions) {
+    @Nullable
+    public <X> T wrap(@Nullable X value, WrapperOptions wrapperOptions) {
         var clazz = getJavaTypeClass();
 
         if (value == null) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/BaseTupleTransformer.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/BaseTupleTransformer.java
new file mode 100644
index 0000000..d655239
--- /dev/null
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/BaseTupleTransformer.java
@@ -0,0 +1,41 @@
+package it.aboutbits.springboot.toolbox.persistence.transformer;
+
+import it.aboutbits.springboot.toolbox.reflection.util.RecordReflectionUtil;
+import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+import java.lang.reflect.InvocationTargetException;
+
+@NullMarked
+abstract class BaseTupleTransformer<T> implements org.hibernate.query.TupleTransformer<T> {
+    protected final Class<T> outputClass;
+
+    protected BaseTupleTransformer(Class<T> outputClass) {
+        this.outputClass = outputClass;
+    }
+
+    @Override
+    public abstract @Nullable T transformTuple(@Nullable Object[] objects, String[] strings);
+
+    protected static <T> boolean isSimpleType(Class<T> outputClass) {
+        return String.class.isAssignableFrom(outputClass)
+                || Float.class.isAssignableFrom(outputClass)
+                || Double.class.isAssignableFrom(outputClass)
+                || Short.class.isAssignableFrom(outputClass)
+                || Integer.class.isAssignableFrom(outputClass)
+                || Long.class.isAssignableFrom(outputClass)
+                || Character.class.isAssignableFrom(outputClass)
+                || Byte.class.isAssignableFrom(outputClass)
+                || Boolean.class.isAssignableFrom(outputClass);
+    }
+
+    protected static <X extends CustomType<?>> X toCustomType(
+            Object actualValue,
+            Class<X> targetType
+    ) throws InvocationTargetException, InstantiationException, IllegalAccessException {
+        var constructor = RecordReflectionUtil.getConstructorForType(targetType, actualValue.getClass());
+
+        return constructor.newInstance(actualValue);
+    }
+}
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/PrimitiveTupleTransformer.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/PrimitiveTupleTransformer.java
new file mode 100644
index 0000000..dd814dd
--- /dev/null
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/PrimitiveTupleTransformer.java
@@ -0,0 +1,29 @@
+package it.aboutbits.springboot.toolbox.persistence.transformer;
+
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+/**
+ * Transformer for real Java primitives or their wrapped counterparts (e.g., long and Long).
+ */
+@NullMarked
+class PrimitiveTupleTransformer<T> extends BaseTupleTransformer<T> {
+
+    PrimitiveTupleTransformer(Class<T> outputClass) {
+        super(outputClass);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public @Nullable T transformTuple(@Nullable Object[] objects, String[] aliases) {
+        if (objects.length != 1) {
+            throw new TransformerRuntimeException("PRIMITIVE mode does not support multiple values!");
+        }
+
+        if (objects[0] == null) {
+            return null;
+        }
+
+        return (T) objects[0];
+    }
+}
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/QueryTransformer.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/QueryTransformer.java
index 1e6994f..07a3603 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/QueryTransformer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/QueryTransformer.java
@@ -2,10 +2,11 @@
 
 import jakarta.persistence.EntityManager;
 import jakarta.persistence.EntityNotFoundException;
-import jakarta.persistence.Query;
 import jakarta.persistence.TypedQuery;
 import org.hibernate.query.NativeQuery;
-import org.hibernate.transform.ResultTransformer;
+import org.hibernate.query.Query;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.Pageable;
@@ -13,24 +14,23 @@
 import java.util.List;
 import java.util.Optional;
 
+@NullMarked
 public final class QueryTransformer<T> {
-
     private final EntityManager entityManager;
     private final TupleTransformer<T> tupleTransformer;
-    private org.hibernate.query.Query<?> unwrappedQuery;
+    private @Nullable Query<?> unwrappedQuery = null;
     private boolean isNative = false;
 
     private QueryTransformer(EntityManager entityManager, Class<T> outputClass) {
         this.entityManager = entityManager;
         this.tupleTransformer = new TupleTransformer<>(outputClass);
-
     }
 
     public static <T> QueryTransformer<T> of(EntityManager entityManager, Class<T> outputClass) {
         return new QueryTransformer<>(entityManager, outputClass);
     }
 
-    public QueryTransformer<T> withQuery(Query query) {
+    public QueryTransformer<T> withQuery(jakarta.persistence.Query query) {
         if (query instanceof NativeQuery<?>) {
             this.isNative = true;
         }
@@ -66,10 +66,13 @@ public T asSingleResultOrFail() {
                 .orElseThrow(EntityNotFoundException::new);
     }
 
-    @SuppressWarnings({"deprecation", "unchecked"})
-    private List<T> asList(Integer pageNumber, Integer pageSize) {
-        unwrappedQuery.setResultTransformer(
-                (ResultTransformer<?>) (objects, aliases) -> tupleTransformer.transform(objects)
+    private List<T> asList(@Nullable Integer pageNumber, @Nullable Integer pageSize) {
+        if (unwrappedQuery == null) {
+            throw new IllegalStateException("Query not set!");
+        }
+
+        unwrappedQuery.setTupleTransformer(
+                tupleTransformer
         );
 
         if (pageSize != null && pageNumber != null) {
@@ -78,10 +81,15 @@ private List<T> asList(Integer pageNumber, Integer pageSize) {
                     .setFirstResult(pageSize * pageNumber);
         }
 
+        // noinspection unchecked
         return (List<T>) unwrappedQuery.getResultList();
     }
 
     private Page<T> asPageQuery(int pageNumber, int pageSize) {
+        if (unwrappedQuery == null) {
+            throw new IllegalStateException("Query not set!");
+        }
+
         var selectPattern = "(?i)select.*?[ \\t]*from ";
         var queryString = unwrappedQuery.getQueryString().trim().replaceAll("\\R", " ");
         var countQueryString = queryString.replaceFirst(selectPattern, "select count(*) from ");
@@ -111,6 +119,10 @@ private Page<T> asPageQuery(int pageNumber, int pageSize) {
     }
 
     private Page<T> asPageNativeQuery(int pageNumber, int pageSize) {
+        if (unwrappedQuery == null) {
+            throw new IllegalStateException("Query not set!");
+        }
+
         var queryString = unwrappedQuery.getQueryString().trim().replaceAll("\\R", " ");
         var countQueryString = "select count(*) from (" + queryString + ") as count";
         var parameters = unwrappedQuery.getParameters();
@@ -147,7 +159,7 @@ private static long getCount(TypedQuery<Long> countQuery, String queryString) {
         return countQueryResults.getFirst();
     }
 
-    private static long getCount(Query countQuery) {
+    private static long getCount(jakarta.persistence.Query countQuery) {
         var countQueryResults = countQuery.getResultList();
         if (countQueryResults == null || countQueryResults.isEmpty()) {
             return 0L;
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TransformerRuntimeException.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TransformerRuntimeException.java
index 95a17d9..1ad68c9 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TransformerRuntimeException.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TransformerRuntimeException.java
@@ -1,5 +1,8 @@
 package it.aboutbits.springboot.toolbox.persistence.transformer;
 
+import org.jspecify.annotations.NullMarked;
+
+@NullMarked
 public class TransformerRuntimeException extends RuntimeException {
     public TransformerRuntimeException() {
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTransformer.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTransformer.java
index 865993a..bb8fe7c 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTransformer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTransformer.java
@@ -1,187 +1,39 @@
 package it.aboutbits.springboot.toolbox.persistence.transformer;
 
-import it.aboutbits.springboot.toolbox.reflection.util.RecordReflectionUtil;
 import it.aboutbits.springboot.toolbox.type.CustomType;
-
-import java.lang.reflect.Constructor;
-import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Modifier;
-import java.time.Instant;
-import java.time.OffsetDateTime;
-import java.time.ZoneId;
-import java.util.Arrays;
-
-public class TupleTransformer<T> {
-    private final Class<T> outputClass;
-    private Constructor<T> outputClassConstructor = null;
-    private Class<?>[] outputClassFieldClasses = null;
-
-    private final Mode mode;
-
-    private enum Mode {
-        PRIMITIVE,  // Real Java primitives or their wrapped counterpart (ex., long and Long)
-        WRAPPED,  // Record with a single wrapped value (CustomType as for example Iban)
-        TUPLE  // Complex tuples with more than one value
-    }
-
-    public TupleTransformer(Class<T> outputClass) {
-        this.outputClass = outputClass;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+/**
+ * Factory class that creates the appropriate tuple transformer based on the output class type.
+ * <p>
+ * This class maintains backward compatibility while delegating to specific transformer implementations:
+ * <ul>
+ *     <li>{@link PrimitiveTupleTransformer} - for Java primitives and their wrapped counterparts</li>
+ *     <li>{@link WrappedTupleTransformer} - for records with a single wrapped value (CustomType)</li>
+ *     <li>{@link TupleTupleTransformer} - for complex tuples with more than one value</li>
+ * </ul>
+ */
+@NullMarked
+class TupleTransformer<T> extends BaseTupleTransformer<T> {
+    private final BaseTupleTransformer<T> delegate;
+
+    TupleTransformer(Class<T> outputClass) {
+        super(outputClass);
 
         // Find all fields and their types inside the result class
         // Ignore constants, because they will not be used as constructor parameters
         if (outputClass.isPrimitive() || isSimpleType(outputClass)) {
-            mode = Mode.PRIMITIVE;
+            delegate = new PrimitiveTupleTransformer<>(outputClass);
         } else if (CustomType.class.isAssignableFrom(outputClass)) {
-            mode = Mode.WRAPPED;
+            delegate = new WrappedTupleTransformer<>(outputClass);
         } else {
-            mode = Mode.TUPLE;
-
-            outputClassFieldClasses = Arrays
-                    .stream(outputClass.getDeclaredFields())
-                    .filter(field -> !Modifier.isStatic(field.getModifiers()))
-                    .map(Field::getType)
-                    .toArray(Class[]::new);
-
-            // Find the all-args-constructor inside the result class
-            try {
-                outputClassConstructor = outputClass.getDeclaredConstructor(outputClassFieldClasses);
-                outputClassConstructor.setAccessible(true);
-            } catch (NoSuchMethodException exception) {
-                throw new TransformerRuntimeException(
-                        String.format(
-                                "Query transformation: Could not find a valid constructor in target class %s",
-                                outputClass.getName()
-                        ),
-                        exception
-                );
-            }
-        }
-    }
-
-    @SuppressWarnings("unchecked")
-    public T transform(Object[] objects) {
-        try {
-            if (Mode.PRIMITIVE.equals(mode)) {
-                if (objects.length != 1) {
-                    throw new TransformerRuntimeException("PRIMITIVE mode does not support multiple values!");
-                }
-                return (T) objects[0];
-            }
-
-            if (Mode.WRAPPED.equals(mode)) {
-                if (objects.length != 1) {
-                    throw new TransformerRuntimeException("WRAPPED mode does not support multiple values!");
-                }
-                return (T) toCustomType(objects[0], (Class<CustomType<?>>) outputClass);
-            }
-
-            // If we have a single entry in the result, and that entry matches the desired result class
-            // we can just give it back, no casting, nor type-checking needed. We can just unbox it and
-            // give it back as-is!
-            // Example: "SELECT p FROM Person p"
-            if (objects.length == 1 && outputClass == objects[0].getClass()) {
-                return (T) objects[0];
-            }
-
-            if (objects.length != outputClassFieldClasses.length) {
-                throw new TransformerRuntimeException(
-                        String.format(
-                                "Invalid query transforming: object count does not match target class field count for %s",
-                                outputClass.getName()
-                        )
-                );
-            }
-
-            // Unboxing not possible, we have a complex combined result, check single record entries for type-safety!
-            for (var i = 0; i < objects.length; i++) {
-
-                // Everything ok, null matches every object and equal classes do not need casting!
-                // Unboxing of primitives is automatic when we call the constructor of the target result class.
-                if (objects[i] == null || outputClassFieldClasses[i].isPrimitive() || objects[i].getClass() == outputClassFieldClasses[i]) {
-                    continue;
-                }
-
-                // Check if the two classes are either the same, or if it is a superclass or superinterface of it...
-                // For example, casting an ArrayList to List can be done directly
-                if (outputClassFieldClasses[i].isAssignableFrom(objects[i].getClass())) {
-                    objects[i] = outputClassFieldClasses[i].cast(objects[i]);
-                    continue;
-                }
-
-                // Converter: STRING to ENUM
-                // A string from the DB, that does not match a corresponding field inside the result class
-                // should probably be an enum value, which implements the "valueOf" interface.
-                if (objects[i] instanceof String && outputClassFieldClasses[i].isEnum()) {
-                    objects[i] = outputClassFieldClasses[i].getMethod("valueOf", String.class).invoke(
-                            null,
-                            objects[i].toString()
-                    );
-                    continue;
-                }
-
-                // Converter: Instant to OffsetDateTime
-                if (objects[i] instanceof Instant instant && outputClassFieldClasses[i].isAssignableFrom(OffsetDateTime.class)) {
-                    objects[i] = OffsetDateTime.ofInstant(
-                            instant,
-                            ZoneId.systemDefault()
-                    );
-                    continue;
-                }
-
-                // Converter: to Records that wrap exactly one value (CustomType)
-                if (CustomType.class.isAssignableFrom(outputClassFieldClasses[i])) {
-                    objects[i] = toCustomType(objects[i], (Class<? extends CustomType<?>>) outputClassFieldClasses[i]);
-                    continue;
-                }
-
-                // Non-matching classes in fields. No converter found...
-                throw new UnsupportedOperationException(
-                        String.format(
-                                "Query transformation: Type mismatch without converter. Cannot cast from %s to %s.",
-                                objects[i].getClass().getName(),
-                                outputClassFieldClasses[i].getName()
-                        )
-                );
-            }
-
-            return outputClassConstructor.newInstance(objects);
-
-        } catch (
-                InstantiationException
-                | IllegalAccessException
-                | NoSuchMethodException
-                | InvocationTargetException
-                | UnsupportedOperationException exception
-        ) {
-            throw new TransformerRuntimeException(
-                    String.format(
-                            "Query transformation: Given database record cannot be converted into target class %s",
-                            outputClass.getName()
-                    ),
-                    exception
-            );
+            delegate = new TupleTupleTransformer<>(outputClass);
         }
     }
 
-    private static <T> boolean isSimpleType(Class<T> outputClass) {
-        return String.class.isAssignableFrom(outputClass)
-                || Float.class.isAssignableFrom(outputClass)
-                || Double.class.isAssignableFrom(outputClass)
-                || Short.class.isAssignableFrom(outputClass)
-                || Integer.class.isAssignableFrom(outputClass)
-                || Long.class.isAssignableFrom(outputClass)
-                || Character.class.isAssignableFrom(outputClass)
-                || Byte.class.isAssignableFrom(outputClass)
-                || Boolean.class.isAssignableFrom(outputClass);
-    }
-
-    private static <X extends CustomType<?>> X toCustomType(
-            Object actualValue,
-            Class<X> targetType
-    ) throws InvocationTargetException, InstantiationException, IllegalAccessException {
-        var constructor = RecordReflectionUtil.getConstructorForType(targetType, actualValue.getClass());
-
-        return constructor.newInstance(actualValue);
+    @Override
+    public @Nullable T transformTuple(@Nullable Object[] objects, String[] aliases) {
+        return delegate.transformTuple(objects, aliases);
     }
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTupleTransformer.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTupleTransformer.java
new file mode 100644
index 0000000..a164d85
--- /dev/null
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTupleTransformer.java
@@ -0,0 +1,162 @@
+package it.aboutbits.springboot.toolbox.persistence.transformer;
+
+import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Modifier;
+import java.time.Instant;
+import java.time.OffsetDateTime;
+import java.time.ZoneId;
+import java.util.Arrays;
+
+/**
+ * Transformer for complex tuples with more than one value (records/classes with multiple fields).
+ */
+@NullMarked
+class TupleTupleTransformer<T> extends BaseTupleTransformer<T> {
+    private final Constructor<T> outputClassConstructor;
+    private final Class<?>[] outputClassFieldClasses;
+
+    TupleTupleTransformer(Class<T> outputClass) {
+        super(outputClass);
+
+        // Find all fields and their types inside the result class
+        // Ignore constants, because they will not be used as constructor parameters
+        outputClassFieldClasses = Arrays
+                .stream(outputClass.getDeclaredFields())
+                .filter(field -> !Modifier.isStatic(field.getModifiers()))
+                .map(Field::getType)
+                .toArray(Class[]::new);
+
+        // Find the all-args-constructor inside the result class
+        try {
+            outputClassConstructor = outputClass.getDeclaredConstructor(outputClassFieldClasses);
+            outputClassConstructor.setAccessible(true);
+        } catch (NoSuchMethodException exception) {
+            throw new TransformerRuntimeException(
+                    String.format(
+                            "Query transformation: Could not find a valid constructor in target class %s",
+                            outputClass.getName()
+                    ),
+                    exception
+            );
+        }
+    }
+
+    @Override
+    public @Nullable T transformTuple(@Nullable Object[] objects, String[] aliases) {
+        try {
+            // If we have a single entry in the result, and that entry matches the desired result class
+            // we can just give it back, no casting, nor type-checking needed. We can just unbox it and
+            // give it back as-is!
+            // Example: "SELECT p FROM Person p"
+            if (objects.length == 1) {
+                if (objects[0] == null) {
+                    return null;
+                }
+                if (outputClass == objects[0].getClass()) {
+                    // noinspection unchecked
+                    return (T) objects[0];
+                }
+            }
+
+            if (objects.length != outputClassFieldClasses.length) {
+                throw new TransformerRuntimeException(
+                        String.format(
+                                "Invalid query transforming: object count does not match target class field count for %s",
+                                outputClass.getName()
+                        )
+                );
+            }
+
+            // Unboxing not possible, we have a complex combined result, check single record entries for type-safety!
+            for (var i = 0; i < objects.length; i++) {
+                transformObject(objects, i);
+            }
+
+            return outputClassConstructor.newInstance(objects);
+        } catch (
+                InstantiationException
+                | IllegalAccessException
+                | NoSuchMethodException
+                | InvocationTargetException
+                | UnsupportedOperationException exception
+        ) {
+            throw new TransformerRuntimeException(
+                    String.format(
+                            "Query transformation: Given database record cannot be converted into target class %s",
+                            outputClass.getName()
+                    ),
+                    exception
+            );
+        }
+    }
+
+    /**
+     * objects are manipulated in-place
+     */
+    private void transformObject(
+            @Nullable Object[] objects,
+            int i
+    ) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException, InstantiationException {
+        var obj = objects[i];
+
+        if (obj == null) {
+            objects[i] = null;
+            return;
+        }
+
+        // Everything ok, null matches every object and equal classes do not need casting!
+        // Unboxing of primitives is automatic when we call the constructor of the target result class.
+        if (outputClassFieldClasses[i].isPrimitive() || obj.getClass() == outputClassFieldClasses[i]) {
+            return;
+        }
+
+        // Check if the two classes are either the same, or if it is a superclass or superinterface of it...
+        // For example, casting an ArrayList to List can be done directly
+        if (outputClassFieldClasses[i].isAssignableFrom(obj.getClass())) {
+            objects[i] = outputClassFieldClasses[i].cast(obj);
+            return;
+        }
+
+        // Converter: STRING to ENUM
+        // A string from the DB, that does not match a corresponding field inside the result class
+        // should probably be an enum value, which implements the "valueOf" interface.
+        if (obj instanceof String && outputClassFieldClasses[i].isEnum()) {
+            objects[i] = outputClassFieldClasses[i].getMethod("valueOf", String.class).invoke(
+                    null,
+                    obj.toString()
+            );
+            return;
+        }
+
+        // Converter: Instant to OffsetDateTime
+        if (obj instanceof Instant instant && outputClassFieldClasses[i].isAssignableFrom(OffsetDateTime.class)) {
+            objects[i] = OffsetDateTime.ofInstant(
+                    instant,
+                    ZoneId.systemDefault()
+            );
+            return;
+        }
+
+        // Converter: to Records that wrap exactly one value (CustomType)
+        if (CustomType.class.isAssignableFrom(outputClassFieldClasses[i])) {
+            // noinspection unchecked
+            objects[i] = toCustomType(obj, (Class<? extends CustomType<?>>) outputClassFieldClasses[i]);
+            return;
+        }
+
+        // Non-matching classes in fields. No converter found...
+        throw new UnsupportedOperationException(
+                String.format(
+                        "Query transformation: Type mismatch without converter. Cannot cast from %s to %s.",
+                        obj.getClass().getName(),
+                        outputClassFieldClasses[i].getName()
+                )
+        );
+    }
+}
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/WrappedTupleTransformer.java b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/WrappedTupleTransformer.java
new file mode 100644
index 0000000..2fae915
--- /dev/null
+++ b/src/main/java/it/aboutbits/springboot/toolbox/persistence/transformer/WrappedTupleTransformer.java
@@ -0,0 +1,44 @@
+package it.aboutbits.springboot.toolbox.persistence.transformer;
+
+import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+import java.lang.reflect.InvocationTargetException;
+
+/**
+ * Transformer for records with a single wrapped value (CustomType, e.g., Iban, EmailAddress).
+ */
+@NullMarked
+class WrappedTupleTransformer<T> extends BaseTupleTransformer<T> {
+
+    WrappedTupleTransformer(Class<T> outputClass) {
+        super(outputClass);
+    }
+
+    @Override
+    public @Nullable T transformTuple(@Nullable Object[] objects, String[] aliases) {
+        try {
+            if (objects.length != 1) {
+                throw new TransformerRuntimeException("WRAPPED mode does not support multiple values!");
+            }
+            if (objects[0] == null) {
+                return null;
+            }
+            // noinspection unchecked
+            return (T) toCustomType(objects[0], (Class<CustomType<?>>) outputClass);
+        } catch (
+                InvocationTargetException
+                | InstantiationException
+                | IllegalAccessException exception
+        ) {
+            throw new TransformerRuntimeException(
+                    String.format(
+                            "Query transformation: Given database record cannot be converted into target class %s",
+                            outputClass.getName()
+                    ),
+                    exception
+            );
+        }
+    }
+}
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/ClassScannerUtil.java b/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/ClassScannerUtil.java
index 4aa3859..eac90c5 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/ClassScannerUtil.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/ClassScannerUtil.java
@@ -3,12 +3,13 @@
 import io.github.classgraph.ClassGraph;
 import io.github.classgraph.ClassInfo;
 import io.github.classgraph.ScanResult;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 
 import java.lang.annotation.Annotation;
 import java.util.Set;
 import java.util.stream.Collectors;
 
+@NullMarked
 public final class ClassScannerUtil {
     private ClassScannerUtil() {
     }
@@ -34,14 +35,14 @@ public String[] getScannedPackages() {
         }
 
         @SuppressWarnings("unchecked")
-        public <T> Set<Class<? extends T>> getSubTypesOf(@NonNull Class<T> clazz) {
+        public <T> Set<Class<? extends T>> getSubTypesOf(Class<T> clazz) {
             return scanResult.getClassesImplementing(clazz).loadClasses()
                     .stream()
                     .map(item -> (Class<? extends T>) item)
                     .collect(Collectors.toSet());
         }
 
-        public Set<Class<?>> getClassesAnnotatedWith(@NonNull Class<? extends Annotation> clazz) {
+        public Set<Class<?>> getClassesAnnotatedWith(Class<? extends Annotation> clazz) {
             var result = scanResult.getClassesWithAnnotation(clazz);
             return result.stream().map(
                     ClassInfo::loadClass
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/CustomTypeReflectionUtil.java b/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/CustomTypeReflectionUtil.java
index a8700a6..3d39ee0 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/CustomTypeReflectionUtil.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/CustomTypeReflectionUtil.java
@@ -1,11 +1,13 @@
 package it.aboutbits.springboot.toolbox.reflection.util;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.ParameterizedType;
 import java.util.Arrays;
 
+@NullMarked
 public final class CustomTypeReflectionUtil {
     private CustomTypeReflectionUtil() {
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/RecordReflectionUtil.java b/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/RecordReflectionUtil.java
index 38e721a..e30a65a 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/RecordReflectionUtil.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/reflection/util/RecordReflectionUtil.java
@@ -1,7 +1,10 @@
 package it.aboutbits.springboot.toolbox.reflection.util;
 
+import org.jspecify.annotations.NullMarked;
+
 import java.lang.reflect.Constructor;
 
+@NullMarked
 public final class RecordReflectionUtil {
     private RecordReflectionUtil() {
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/SwaggerMeta.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/SwaggerMeta.java
index 0198863..f2786a5 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/SwaggerMeta.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/SwaggerMeta.java
@@ -4,19 +4,34 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import lombok.Getter;
 import lombok.Setter;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+// JsonProperty on boolean fields is required or it will interpret the name as a getter and remove the "is".
 @Getter
 @Setter
 @JsonInclude(JsonInclude.Include.NON_NULL)
+@NullMarked
 public class SwaggerMeta {
+    @Nullable
     private String originalTypeFqn = null;
+
+    @Nullable
     @JsonProperty("isIdentity")
     private Boolean isIdentity = null;
+
+    @Nullable
     @JsonProperty("isCustomType")
     private Boolean isCustomType = null;
+
+    @Nullable
     @JsonProperty("isNestedStructure")
     private Boolean isNestedStructure = null;
+
+    @Nullable
     @JsonProperty("isMap")
     private Boolean isMap = null;
+
+    @Nullable
     private String mapKeyTypeFqn = null;
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/SwaggerMetaUtil.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/SwaggerMetaUtil.java
index f1d46ed..45dd0d7 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/SwaggerMetaUtil.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/SwaggerMetaUtil.java
@@ -2,12 +2,13 @@
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import lombok.NonNull;
 import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.lang.Nullable;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 @Slf4j
+@NullMarked
 public final class SwaggerMetaUtil {
     private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
 
@@ -15,7 +16,7 @@ private SwaggerMetaUtil() {
     }
 
     @SneakyThrows(JsonProcessingException.class)
-    public static String setMapKeyTypeFqn(@Nullable String currentMeta, @NonNull String value) {
+    public static String setMapKeyTypeFqn(@Nullable String currentMeta, String value) {
         var meta = getSwaggerMeta(currentMeta);
         meta.setMapKeyTypeFqn(value);
 
@@ -31,7 +32,7 @@ public static String setIsMap(@Nullable String currentMeta, boolean value) {
     }
 
     @SneakyThrows(JsonProcessingException.class)
-    public static String setOriginalTypeFqn(@Nullable String currentMeta, @NonNull String value) {
+    public static String setOriginalTypeFqn(@Nullable String currentMeta, String value) {
         var meta = getSwaggerMeta(currentMeta);
         meta.setOriginalTypeFqn(value);
 
@@ -62,7 +63,7 @@ public static String setIsNestedStructure(@Nullable String currentMeta, boolean
         return OBJECT_MAPPER.writeValueAsString(meta);
     }
 
-    private static SwaggerMeta getSwaggerMeta(String currentMeta) {
+    private static SwaggerMeta getSwaggerMeta(@Nullable String currentMeta) {
         var meta = new SwaggerMeta();
         if (currentMeta != null) {
             try {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/annotation/ForceSwaggerSchema.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/annotation/ForceSwaggerSchema.java
index 0688108..92ecabf 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/annotation/ForceSwaggerSchema.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/annotation/ForceSwaggerSchema.java
@@ -1,5 +1,7 @@
 package it.aboutbits.springboot.toolbox.swagger.annotation;
 
+import org.jspecify.annotations.NullMarked;
+
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -10,6 +12,7 @@
  */
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)
+@NullMarked
 public @interface ForceSwaggerSchema {
 
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/alphabetical_model_order/OrderModelsCustomizer.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/alphabetical_model_order/OrderModelsCustomizer.java
index d1bc35e..324f50e 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/alphabetical_model_order/OrderModelsCustomizer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/alphabetical_model_order/OrderModelsCustomizer.java
@@ -1,10 +1,12 @@
 package it.aboutbits.springboot.toolbox.swagger.customization.alphabetical_model_order;
 
 import io.swagger.v3.oas.models.OpenAPI;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.OpenApiCustomizer;
 
 import java.util.TreeMap;
 
+@NullMarked
 public class OrderModelsCustomizer implements OpenApiCustomizer {
     @Override
     public void customise(OpenAPI openApi) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeModelConverter.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeModelConverter.java
index 4181a6c..ecab614 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeModelConverter.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeModelConverter.java
@@ -10,16 +10,20 @@
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
 import it.aboutbits.springboot.toolbox.type.identity.EntityId;
 import lombok.SneakyThrows;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.util.Iterator;
 import java.util.UUID;
 
+@NullMarked
 public class CustomTypeModelConverter implements ModelConverter {
 
     @Override
     @SneakyThrows(NoSuchMethodException.class)
+    @Nullable
     public Schema<?> resolve(
             AnnotatedType annotatedType,
             ModelConverterContext context,
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeOpenApiCustomizerForCodeGenerator.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeOpenApiCustomizerForCodeGenerator.java
index 5ac7f00..71f1192 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeOpenApiCustomizerForCodeGenerator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeOpenApiCustomizerForCodeGenerator.java
@@ -6,18 +6,19 @@
 import it.aboutbits.springboot.toolbox.type.CustomType;
 import it.aboutbits.springboot.toolbox.type.identity.EntityId;
 import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.OpenApiCustomizer;
 
 import static it.aboutbits.springboot.toolbox.swagger.customization.custom_type.SchemaUtil.getClassFromSchemaReference;
 
 @Slf4j
+@NullMarked
 public class CustomTypeOpenApiCustomizerForCodeGenerator implements OpenApiCustomizer {
     @Override
     public void customise(OpenAPI openApi) {
         openApi.getComponents().getSchemas().forEach(this::updateSchema);
     }
 
-
     private void updateSchema(String fqn, Schema<?> schema) {
         var type = getClassFromSchemaReference(fqn);
 
@@ -40,6 +41,5 @@ private void updateSchema(String fqn, Schema<?> schema) {
             description = SwaggerMetaUtil.setIsCustomType(description, true);
             schema.setDescription(description);
         }
-
     }
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeParameterCustomizer.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeParameterCustomizer.java
index fe4e5d4..99631cb 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeParameterCustomizer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeParameterCustomizer.java
@@ -10,6 +10,8 @@
 import it.aboutbits.springboot.toolbox.type.identity.EntityId;
 import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springdoc.core.customizers.ParameterCustomizer;
 import org.springframework.core.MethodParameter;
 
@@ -20,11 +22,13 @@
 import static it.aboutbits.springboot.toolbox.swagger.customization.custom_type.SchemaUtil.getClassFromSchemaReference;
 
 @Slf4j
+@NullMarked
 public class CustomTypeParameterCustomizer implements ParameterCustomizer {
     @SuppressWarnings("checkstyle:MethodLength")
     @Override
     @SneakyThrows(NoSuchMethodException.class)
-    public Parameter customize(Parameter parameter, MethodParameter methodParameter) {
+    @Nullable
+    public Parameter customize(@Nullable Parameter parameter, MethodParameter methodParameter) {
         if (parameter == null) {
             return null;
         }
@@ -56,7 +60,6 @@ public Parameter customize(Parameter parameter, MethodParameter methodParameter)
             return parameter;
         }
 
-
         var rawClass = optionalClass.get();
 
         if (rawClass.getName().contains(".") && !rawClass.getName().startsWith("java.")) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeParameterCustomizerForCodeGenerator.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeParameterCustomizerForCodeGenerator.java
index dfe39de..37b01a2 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeParameterCustomizerForCodeGenerator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypeParameterCustomizerForCodeGenerator.java
@@ -5,16 +5,20 @@
 import io.swagger.v3.oas.models.parameters.Parameter;
 import it.aboutbits.springboot.toolbox.swagger.SwaggerMetaUtil;
 import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springdoc.core.customizers.ParameterCustomizer;
 import org.springframework.core.MethodParameter;
 
 import static it.aboutbits.springboot.toolbox.swagger.customization.custom_type.SchemaUtil.getClassFromSchemaReference;
 
 @Slf4j
+@NullMarked
 public class CustomTypeParameterCustomizerForCodeGenerator implements ParameterCustomizer {
     @SuppressWarnings("checkstyle:MethodLength")
     @Override
-    public Parameter customize(Parameter parameter, MethodParameter methodParameter) {
+    @Nullable
+    public Parameter customize(@Nullable Parameter parameter, MethodParameter methodParameter) {
         if (parameter == null) {
             return null;
         }
@@ -46,7 +50,6 @@ public Parameter customize(Parameter parameter, MethodParameter methodParameter)
             return parameter;
         }
 
-
         var rawClass = optionalClass.get();
 
         if (rawClass.getName().contains(".") && !rawClass.getName().startsWith("java.")) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypePropertyCustomizer.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypePropertyCustomizer.java
index 093a926..12a83f0 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypePropertyCustomizer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypePropertyCustomizer.java
@@ -10,6 +10,7 @@
 import it.aboutbits.springboot.toolbox.type.identity.EntityId;
 import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.PropertyCustomizer;
 
 import java.math.BigDecimal;
@@ -17,6 +18,7 @@
 import java.util.UUID;
 
 @Slf4j
+@NullMarked
 public class CustomTypePropertyCustomizer implements PropertyCustomizer {
     @Override
     @SneakyThrows(NoSuchMethodException.class)
@@ -34,7 +36,7 @@ public Schema<?> customize(Schema property, AnnotatedType annotatedType) {
             }
 
             if (CustomType.class.isAssignableFrom(rawClass)) {
-                Class<?> wrappedType = null;
+                Class<?> wrappedType;
                 if (rawClass.equals(EntityId.class)) {
                     wrappedType = simpleType.getBindings()
                             .getTypeParameters()
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypePropertyCustomizerForCodeGenerator.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypePropertyCustomizerForCodeGenerator.java
index 283d7c3..a3781d0 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypePropertyCustomizerForCodeGenerator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/CustomTypePropertyCustomizerForCodeGenerator.java
@@ -4,8 +4,10 @@
 import io.swagger.v3.core.converter.AnnotatedType;
 import io.swagger.v3.oas.models.media.Schema;
 import it.aboutbits.springboot.toolbox.swagger.SwaggerMetaUtil;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.PropertyCustomizer;
 
+@NullMarked
 public class CustomTypePropertyCustomizerForCodeGenerator implements PropertyCustomizer {
     @Override
     public Schema<?> customize(Schema property, AnnotatedType annotatedType) {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/SchemaUtil.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/SchemaUtil.java
index 25e54ca..339118a 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/SchemaUtil.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/custom_type/SchemaUtil.java
@@ -1,7 +1,10 @@
 package it.aboutbits.springboot.toolbox.swagger.customization.custom_type;
 
+import org.jspecify.annotations.NullMarked;
+
 import java.util.Optional;
 
+@NullMarked
 final class SchemaUtil {
     private SchemaUtil() {
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/default_not_null/NullableCustomizer.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/default_not_null/NullableCustomizer.java
index a51b946..9ee0dde 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/default_not_null/NullableCustomizer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/default_not_null/NullableCustomizer.java
@@ -2,11 +2,13 @@
 
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.media.Schema;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.OpenApiCustomizer;
 
 import java.util.ArrayList;
 import java.util.Map;
 
+@NullMarked
 public class NullableCustomizer implements OpenApiCustomizer {
     public static final String NULLABLE_MARKER = "NULLABLE";
 
@@ -68,7 +70,7 @@ private static boolean isNullable(Schema<?> property) {
 
         if (property.getItems() != null && property.getItems().get$ref() != null && property.getItems()
                 .get$ref()
-                .endsWith("?nullable=true")) {
+                .endsWith(NULLABLE_MARKER)) {
             return true;
         }
 
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/default_not_null/NullablePropertyCustomizer.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/default_not_null/NullablePropertyCustomizer.java
index bb5ea21..f0418b0 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/default_not_null/NullablePropertyCustomizer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/default_not_null/NullablePropertyCustomizer.java
@@ -3,6 +3,7 @@
 import io.swagger.v3.core.converter.AnnotatedType;
 import io.swagger.v3.core.jackson.ModelResolver;
 import io.swagger.v3.oas.models.media.Schema;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.PropertyCustomizer;
 import org.springframework.stereotype.Component;
 
@@ -18,6 +19,7 @@
  * This customizer adds a nullability maker. Later we process this to manipulate the required fields of a schema.
  */
 @Component
+@NullMarked
 public class NullablePropertyCustomizer implements PropertyCustomizer {
     static {
         /*
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/force_schema/ForceSchemaCustomizer.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/force_schema/ForceSchemaCustomizer.java
index 6ea33e7..548437e 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/force_schema/ForceSchemaCustomizer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/force_schema/ForceSchemaCustomizer.java
@@ -9,6 +9,7 @@
 import it.aboutbits.springboot.toolbox.swagger.annotation.ForceSwaggerSchema;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.OpenApiCustomizer;
 
 import java.util.Arrays;
@@ -16,6 +17,7 @@
 
 @RequiredArgsConstructor
 @Slf4j
+@NullMarked
 public class ForceSchemaCustomizer implements OpenApiCustomizer {
     private final ModelResolver modelResolver;
     private final ClassScannerUtil.ClassScanner classScanner;
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/logout_route/LogoutCustomizer.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/logout_route/LogoutCustomizer.java
index ab8522c..0aae31b 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/logout_route/LogoutCustomizer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/logout_route/LogoutCustomizer.java
@@ -4,15 +4,16 @@
 import io.swagger.v3.oas.models.Operation;
 import io.swagger.v3.oas.models.PathItem;
 import io.swagger.v3.oas.models.responses.ApiResponses;
-import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.OpenApiCustomizer;
 
 @RequiredArgsConstructor
+@NullMarked
 public class LogoutCustomizer implements OpenApiCustomizer {
-    @NonNull
+
     private final String logoutUrl;
-    @NonNull
+
     private final String tag;
 
     @Override
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/nested_structure/NestedStructuresCustomizer.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/nested_structure/NestedStructuresCustomizer.java
index cf449b3..3055f76 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/nested_structure/NestedStructuresCustomizer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/customization/nested_structure/NestedStructuresCustomizer.java
@@ -2,12 +2,14 @@
 
 import io.swagger.v3.oas.models.OpenAPI;
 import it.aboutbits.springboot.toolbox.swagger.SwaggerMetaUtil;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.OpenApiCustomizer;
 
 /**
  * We assume that records that are inner classes of other records should be treated as substructure.
  * As such, we set the corresponding metadata for the FE code-generator.
  */
+@NullMarked
 public class NestedStructuresCustomizer implements OpenApiCustomizer {
     @Override
     public void customise(OpenAPI openApi) {
@@ -25,7 +27,6 @@ public void customise(OpenAPI openApi) {
                                     true
                             ));
                         }
-
                     } catch (ClassNotFoundException ignored) {
                         // do nothing
                     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/resolver/CustomModelResolver.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/resolver/CustomModelResolver.java
index e6808a6..0236e01 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/resolver/CustomModelResolver.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/resolver/CustomModelResolver.java
@@ -3,7 +3,9 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import io.swagger.v3.core.jackson.ModelResolver;
 import io.swagger.v3.core.jackson.TypeNameResolver;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public class CustomModelResolver extends ModelResolver {
     public CustomModelResolver(ObjectMapper mapper) {
         super(mapper, new CustomTypeNameResolver());
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/swagger/sort_parameter/SortParameterCustomizer.java b/src/main/java/it/aboutbits/springboot/toolbox/swagger/sort_parameter/SortParameterCustomizer.java
index 0feaaea..621d3ed 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/swagger/sort_parameter/SortParameterCustomizer.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/swagger/sort_parameter/SortParameterCustomizer.java
@@ -4,8 +4,10 @@
 import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.StringSchema;
 import it.aboutbits.springboot.toolbox.parameter.SortParameter;
+import org.jspecify.annotations.NullMarked;
 import org.springdoc.core.customizers.OpenApiCustomizer;
 
+@NullMarked
 public class SortParameterCustomizer implements OpenApiCustomizer {
     private final String nameToMatch = "." + SortParameter.class.getSimpleName();
 
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/type/CustomType.java b/src/main/java/it/aboutbits/springboot/toolbox/type/CustomType.java
index 130a537..4614845 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/type/CustomType.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/type/CustomType.java
@@ -1,10 +1,13 @@
 package it.aboutbits.springboot.toolbox.type;
 
+import org.jspecify.annotations.NullMarked;
+
 /**
  * Implementations should override `toString()` by forwarding
  * the `toString()` method of the wrapped value.
  * Or return `Objects.toString(value())`
  */
+@NullMarked
 public interface CustomType<T> {
     T value();
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/type/EmailAddress.java b/src/main/java/it/aboutbits/springboot/toolbox/type/EmailAddress.java
index 78245aa..14dbc32 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/type/EmailAddress.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/type/EmailAddress.java
@@ -1,7 +1,8 @@
 package it.aboutbits.springboot.toolbox.type;
 
 import it.aboutbits.springboot.toolbox.validation.util.EmailAddressValidator;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 /**
  * A record representing an email address, validated and stored in lowercase.
@@ -15,8 +16,9 @@
  * @param value the email address string
  * @throws IllegalArgumentException if the provided email address is not in a valid format
  */
+@NullMarked
 public record EmailAddress(String value) implements CustomType<String>, Comparable<EmailAddress> {
-    public EmailAddress(String value) {
+    public EmailAddress(@Nullable String value) {
         if (value == null || EmailAddressValidator.isNotValid(value)) {
             throw new IllegalArgumentException("Value is not a valid email address: " + value);
         }
@@ -24,14 +26,13 @@ public EmailAddress(String value) {
         this.value = value.toLowerCase();
     }
 
-    @NonNull
     @Override
     public String toString() {
         return value;
     }
 
     @Override
-    public int compareTo(@NonNull EmailAddress o) {
+    public int compareTo(EmailAddress o) {
         return value().compareTo(o.value());
     }
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/type/Iban.java b/src/main/java/it/aboutbits/springboot/toolbox/type/Iban.java
index a180661..44daf9d 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/type/Iban.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/type/Iban.java
@@ -1,7 +1,8 @@
 package it.aboutbits.springboot.toolbox.type;
 
 import it.aboutbits.springboot.toolbox.validation.util.IbanValidator;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.util.Optional;
 
@@ -11,8 +12,9 @@
  *
  * @param value the IBAN value, which must be a valid and non-null string
  */
+@NullMarked
 public record Iban(String value) implements CustomType<String>, Comparable<Iban> {
-    public Iban(String value) {
+    public Iban(@Nullable String value) {
         if (value == null || IbanValidator.isNotValid(value.toUpperCase())) {
             throw new IllegalArgumentException("Value is not a valid IBAN: " + value);
         }
@@ -20,7 +22,6 @@ public Iban(String value) {
         this.value = value.toUpperCase();
     }
 
-    @NonNull
     @Override
     public String toString() {
         return value;
@@ -31,7 +32,7 @@ public String toString() {
      *
      * @return An {@code Optional} containing the ABI value if the IBAN is Italian, or an empty {@code Optional} otherwise.
      */
-    @NonNull
+
     public Optional<String> getAbiIfItalian() {
         var iban = value();
 
@@ -42,7 +43,7 @@ public Optional<String> getAbiIfItalian() {
     }
 
     @Override
-    public int compareTo(@NonNull Iban o) {
+    public int compareTo(Iban o) {
         return value().compareTo(o.value());
     }
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/type/ScaledBigDecimal.java b/src/main/java/it/aboutbits/springboot/toolbox/type/ScaledBigDecimal.java
index 9c32abd..7f24b0b 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/type/ScaledBigDecimal.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/type/ScaledBigDecimal.java
@@ -1,6 +1,6 @@
 package it.aboutbits.springboot.toolbox.type;
 
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
@@ -12,8 +12,9 @@
  * This class provides various constructors for creating instances with different numerical types.
  * It also provides a set of arithmetic operations that return new instances with the appropriate scale and rounding.
  */
+@NullMarked
 public record ScaledBigDecimal(
-        @NonNull BigDecimal value
+        BigDecimal value
 ) implements CustomType<BigDecimal>, Comparable<ScaledBigDecimal> {
     private static final MathContext MATH_CONTEXT = new MathContext(15, RoundingMode.HALF_UP);
 
@@ -22,7 +23,7 @@ public record ScaledBigDecimal(
     public static final ScaledBigDecimal TWO = new ScaledBigDecimal(2);
     public static final ScaledBigDecimal TEN = new ScaledBigDecimal(10);
 
-    public ScaledBigDecimal(@NonNull BigDecimal value) {
+    public ScaledBigDecimal(BigDecimal value) {
         this.value = value.setScale(MATH_CONTEXT.getPrecision(), MATH_CONTEXT.getRoundingMode());
     }
 
@@ -30,11 +31,11 @@ public ScaledBigDecimal(int value) {
         this(new BigDecimal(value, MATH_CONTEXT));
     }
 
-    public ScaledBigDecimal(@NonNull Integer value) {
+    public ScaledBigDecimal(Integer value) {
         this(new BigDecimal(value, MATH_CONTEXT));
     }
 
-    public ScaledBigDecimal(@NonNull BigInteger value) {
+    public ScaledBigDecimal(BigInteger value) {
         this(new BigDecimal(value, MATH_CONTEXT));
     }
 
@@ -42,7 +43,7 @@ public ScaledBigDecimal(long value) {
         this(new BigDecimal(value, MATH_CONTEXT));
     }
 
-    public ScaledBigDecimal(@NonNull Long value) {
+    public ScaledBigDecimal(Long value) {
         this(new BigDecimal(value, MATH_CONTEXT));
     }
 
@@ -50,7 +51,7 @@ public ScaledBigDecimal(float value) {
         this(new BigDecimal(String.valueOf(value), MATH_CONTEXT));
     }
 
-    public ScaledBigDecimal(@NonNull Float value) {
+    public ScaledBigDecimal(Float value) {
         this(new BigDecimal(String.valueOf(value), MATH_CONTEXT));
     }
 
@@ -58,11 +59,11 @@ public ScaledBigDecimal(double value) {
         this(new BigDecimal(String.valueOf(value), MATH_CONTEXT));
     }
 
-    public ScaledBigDecimal(@NonNull Double value) {
+    public ScaledBigDecimal(Double value) {
         this(new BigDecimal(String.valueOf(value), MATH_CONTEXT));
     }
 
-    public ScaledBigDecimal(@NonNull String value) {
+    public ScaledBigDecimal(String value) {
         this(new BigDecimal(value, MATH_CONTEXT));
     }
 
@@ -70,11 +71,11 @@ public static ScaledBigDecimal valueOf(int value) {
         return new ScaledBigDecimal(value);
     }
 
-    public static ScaledBigDecimal valueOf(@NonNull Integer value) {
+    public static ScaledBigDecimal valueOf(Integer value) {
         return new ScaledBigDecimal(value);
     }
 
-    public static ScaledBigDecimal valueOf(@NonNull BigInteger value) {
+    public static ScaledBigDecimal valueOf(BigInteger value) {
         return new ScaledBigDecimal(value);
     }
 
@@ -82,7 +83,7 @@ public static ScaledBigDecimal valueOf(long value) {
         return new ScaledBigDecimal(value);
     }
 
-    public static ScaledBigDecimal valueOf(@NonNull Long value) {
+    public static ScaledBigDecimal valueOf(Long value) {
         return new ScaledBigDecimal(value);
     }
 
@@ -90,7 +91,7 @@ public static ScaledBigDecimal valueOf(float value) {
         return new ScaledBigDecimal(value);
     }
 
-    public static ScaledBigDecimal valueOf(@NonNull Float value) {
+    public static ScaledBigDecimal valueOf(Float value) {
         return new ScaledBigDecimal(value);
     }
 
@@ -98,116 +99,95 @@ public static ScaledBigDecimal valueOf(double value) {
         return new ScaledBigDecimal(value);
     }
 
-    public static ScaledBigDecimal valueOf(@NonNull Double value) {
+    public static ScaledBigDecimal valueOf(Double value) {
         return new ScaledBigDecimal(value);
     }
 
-    public static ScaledBigDecimal valueOf(@NonNull String value) {
+    public static ScaledBigDecimal valueOf(String value) {
         return new ScaledBigDecimal(value);
     }
 
-    @NonNull
-    public ScaledBigDecimal add(@NonNull ScaledBigDecimal other) {
+    public ScaledBigDecimal add(ScaledBigDecimal other) {
         return new ScaledBigDecimal(this.value().add(other.value()));
     }
 
-    @NonNull
-    public ScaledBigDecimal subtract(@NonNull ScaledBigDecimal other) {
+    public ScaledBigDecimal subtract(ScaledBigDecimal other) {
         return new ScaledBigDecimal(this.value().subtract(other.value()));
     }
 
-    @NonNull
-    public ScaledBigDecimal multiply(@NonNull ScaledBigDecimal other) {
+    public ScaledBigDecimal multiply(ScaledBigDecimal other) {
         return new ScaledBigDecimal(this.value().multiply(other.value()));
     }
 
-    @NonNull
-    public ScaledBigDecimal divide(@NonNull ScaledBigDecimal other) {
+    public ScaledBigDecimal divide(ScaledBigDecimal other) {
         return new ScaledBigDecimal(this.value().divide(other.value(), MATH_CONTEXT));
     }
 
-    @NonNull
-    public ScaledBigDecimal add(@NonNull BigDecimal other) {
+    public ScaledBigDecimal add(BigDecimal other) {
         return new ScaledBigDecimal(this.value().add(other));
     }
 
-    @NonNull
-    public ScaledBigDecimal subtract(@NonNull BigDecimal other) {
+    public ScaledBigDecimal subtract(BigDecimal other) {
         return new ScaledBigDecimal(this.value().subtract(other));
     }
 
-    @NonNull
-    public ScaledBigDecimal multiply(@NonNull BigDecimal other) {
+    public ScaledBigDecimal multiply(BigDecimal other) {
         return new ScaledBigDecimal(this.value().multiply(other));
     }
 
-    @NonNull
-    public ScaledBigDecimal divide(@NonNull BigDecimal other) {
+    public ScaledBigDecimal divide(BigDecimal other) {
         return new ScaledBigDecimal(this.value().divide(other, MATH_CONTEXT));
     }
 
-    @NonNull
-    public ScaledBigDecimal remainder(@NonNull ScaledBigDecimal divisor) {
+    public ScaledBigDecimal remainder(ScaledBigDecimal divisor) {
         return new ScaledBigDecimal(this.value().remainder(divisor.value(), MATH_CONTEXT));
     }
 
-    @NonNull
-    public ScaledBigDecimal remainder(@NonNull BigDecimal divisor) {
+    public ScaledBigDecimal remainder(BigDecimal divisor) {
         return new ScaledBigDecimal(this.value().remainder(divisor, MATH_CONTEXT));
     }
 
-    @NonNull
     public ScaledBigDecimal sqrt() {
         return new ScaledBigDecimal(this.value().sqrt(MATH_CONTEXT));
     }
 
-    @NonNull
     public ScaledBigDecimal pow(int n) {
         return new ScaledBigDecimal(this.value().pow(n, MATH_CONTEXT));
     }
 
-    @NonNull
     public ScaledBigDecimal abs() {
         return new ScaledBigDecimal(this.value().abs(MATH_CONTEXT));
     }
 
-    @NonNull
     public ScaledBigDecimal negate() {
         return new ScaledBigDecimal(this.value().negate(MATH_CONTEXT));
     }
 
-    @NonNull
-    public ScaledBigDecimal min(@NonNull ScaledBigDecimal val) {
+    public ScaledBigDecimal min(ScaledBigDecimal val) {
         return new ScaledBigDecimal(this.value().min(val.value()));
     }
 
-    @NonNull
-    public ScaledBigDecimal min(@NonNull BigDecimal val) {
+    public ScaledBigDecimal min(BigDecimal val) {
         return new ScaledBigDecimal(this.value().min(val));
     }
 
-    @NonNull
-    public ScaledBigDecimal max(@NonNull ScaledBigDecimal val) {
+    public ScaledBigDecimal max(ScaledBigDecimal val) {
         return new ScaledBigDecimal(this.value().max(val.value()));
     }
 
-    @NonNull
-    public ScaledBigDecimal max(@NonNull BigDecimal val) {
+    public ScaledBigDecimal max(BigDecimal val) {
         return new ScaledBigDecimal(this.value().max(val));
     }
 
-    @NonNull
     public BigDecimal toBigDecimal(int scale) {
         return this.value().setScale(scale, RoundingMode.HALF_UP);
     }
 
-    @NonNull
     public ScaledBigDecimal roundToScale(int scale) {
         return new ScaledBigDecimal(this.value().setScale(scale, RoundingMode.HALF_UP));
     }
 
     @Override
-    @NonNull
     public String toString() {
         return this.value().toString();
     }
@@ -231,7 +211,7 @@ public int hashCode() {
     }
 
     @Override
-    public int compareTo(@NonNull ScaledBigDecimal o) {
+    public int compareTo(ScaledBigDecimal o) {
         return this.value().compareTo(o.value());
     }
 
@@ -240,7 +220,6 @@ public int compareTo(@NonNull ScaledBigDecimal o) {
      * This is temporary. We need to avoid changing any rounding logic at the moment.
      */
     @Deprecated
-    @NonNull
     public BigDecimal toCurrency() {
         return this.value().setScale(2, RoundingMode.HALF_UP);
     }
@@ -250,7 +229,6 @@ public BigDecimal toCurrency() {
      * This is temporary. We need to avoid changing any rounding logic at the moment.
      */
     @Deprecated
-    @NonNull
     public ScaledBigDecimal roundToCurrency() {
         return new ScaledBigDecimal(this.value().setScale(2, RoundingMode.HALF_UP));
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/type/identity/EntityId.java b/src/main/java/it/aboutbits/springboot/toolbox/type/identity/EntityId.java
index 4f8ad59..d3fc6ed 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/type/identity/EntityId.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/type/identity/EntityId.java
@@ -1,6 +1,7 @@
 package it.aboutbits.springboot.toolbox.type.identity;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
 import java.io.Serializable;
 
@@ -10,5 +11,6 @@
  *
  * @param <T> the type of the value being wrapped
  */
+@NullMarked
 public interface EntityId<T> extends CustomType<T>, Serializable {
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/type/identity/Identified.java b/src/main/java/it/aboutbits/springboot/toolbox/type/identity/Identified.java
index 6d0613b..941a587 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/type/identity/Identified.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/type/identity/Identified.java
@@ -1,5 +1,10 @@
 package it.aboutbits.springboot.toolbox.type.identity;
 
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+@NullMarked
 public interface Identified<ID extends EntityId<?>> {
+    @Nullable
     ID getId();
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/util/CollectUtil.java b/src/main/java/it/aboutbits/springboot/toolbox/util/CollectUtil.java
index 42f7ed0..5631699 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/util/CollectUtil.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/util/CollectUtil.java
@@ -1,6 +1,7 @@
 package it.aboutbits.springboot.toolbox.util;
 
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.util.Streamable;
 
 import java.util.Collection;
@@ -18,74 +19,84 @@
  * <p>
  * The returned collections are unmodifiable.
  */
+@NullMarked
 public final class CollectUtil {
     private CollectUtil() {
     }
 
-    public static <T, R> Set<R> collectToSet(@NonNull Collection<T> items, @NonNull Function<T, R> mapper) {
+    public static <T, R> Set<R> collectToSet(Collection<T> items, NullableFunction<? super T, R> mapper) {
         return items.stream()
-                .map(mapper)
+                .map(mapper::apply)
                 .filter(Objects::nonNull)
                 .collect(Collectors.toUnmodifiableSet());
     }
 
-    public static <T, R> Set<R> collectToSet(@NonNull Streamable<T> items, @NonNull Function<T, R> mapper) {
+    public static <T, R> Set<R> collectToSet(Streamable<T> items, NullableFunction<? super T, R> mapper) {
         return items.stream()
-                .map(mapper)
+                .map(mapper::apply)
                 .filter(Objects::nonNull)
                 .collect(Collectors.toUnmodifiableSet());
     }
 
-    public static <T, R> Set<R> collectToSet(@NonNull Stream<T> items, @NonNull Function<T, R> mapper) {
+    public static <T, R> Set<R> collectToSet(Stream<T> items, NullableFunction<? super T, R> mapper) {
         return items
-                .map(mapper)
+                .map(mapper::apply)
                 .filter(Objects::nonNull)
                 .collect(Collectors.toUnmodifiableSet());
     }
 
-    public static <T, R> List<R> collectToList(@NonNull Collection<T> items, @NonNull Function<T, R> mapper) {
+    @SuppressWarnings("java:S6204")
+    public static <T, R> List<R> collectToList(Collection<T> items, NullableFunction<? super T, R> mapper) {
+        //noinspection SimplifyStreamApiCallChains
         return items.stream()
-                .map(mapper)
+                .map(mapper::apply)
                 .filter(Objects::nonNull)
-                .toList();
+                .collect(Collectors.toUnmodifiableList());
     }
 
-    public static <T, R> List<R> collectToList(@NonNull Streamable<T> items, @NonNull Function<T, R> mapper) {
+    @SuppressWarnings("java:S6204")
+    public static <T, R> List<R> collectToList(Streamable<T> items, NullableFunction<? super T, R> mapper) {
+        //noinspection SimplifyStreamApiCallChains
         return items.stream()
-                .map(mapper)
+                .map(mapper::apply)
                 .filter(Objects::nonNull)
-                .toList();
+                .collect(Collectors.toUnmodifiableList());
     }
 
-    public static <T, R> List<R> collectToList(@NonNull Stream<T> items, @NonNull Function<T, R> mapper) {
+    @SuppressWarnings("java:S6204")
+    public static <T, R> List<R> collectToList(Stream<T> items, NullableFunction<? super T, R> mapper) {
+        //noinspection SimplifyStreamApiCallChains
         return items
-                .map(mapper)
+                .map(mapper::apply)
                 .filter(Objects::nonNull)
-                .toList();
+                .collect(Collectors.toUnmodifiableList());
     }
 
-    public static <T, R> Stream<R> collectToStream(@NonNull Collection<T> items, @NonNull Function<T, R> mapper) {
+    public static <T, R> Stream<R> collectToStream(Collection<T> items, NullableFunction<? super T, R> mapper) {
+        //noinspection NullableProblems
         return items.stream()
-                .map(mapper)
+                .map(mapper::apply)
                 .filter(Objects::nonNull);
     }
 
-    public static <T, R> Stream<R> collectToStream(@NonNull Streamable<T> items, @NonNull Function<T, R> mapper) {
+    public static <T, R> Stream<R> collectToStream(Streamable<T> items, NullableFunction<? super T, R> mapper) {
+        //noinspection NullableProblems
         return items.stream()
-                .map(mapper)
+                .map(mapper::apply)
                 .filter(Objects::nonNull);
     }
 
-    public static <T, R> Stream<R> collectToStream(@NonNull Stream<T> items, @NonNull Function<T, R> mapper) {
+    public static <T, R> Stream<R> collectToStream(Stream<T> items, NullableFunction<? super T, R> mapper) {
+        //noinspection NullableProblems
         return items
-                .map(mapper)
+                .map(mapper::apply)
                 .filter(Objects::nonNull);
     }
 
     public static <T, K, R> Map<K, R> collectToMap(
-            @NonNull Collection<T> items,
-            @NonNull Function<T, K> keyMapper,
-            @NonNull Function<T, R> valueMapper
+            Collection<@Nullable T> items,
+            Function<T, K> keyMapper,
+            Function<T, R> valueMapper
     ) {
         return items.stream()
                 .filter(Objects::nonNull)
@@ -93,19 +104,18 @@ public static <T, K, R> Map<K, R> collectToMap(
     }
 
     public static <T, K, R> Map<K, R> collectToMap(
-            @NonNull Streamable<T> items,
-            @NonNull Function<T, K> keyMapper,
-            @NonNull Function<T, R> valueMapper
+            Streamable<T> items,
+            Function<T, K> keyMapper,
+            Function<T, R> valueMapper
     ) {
         return items.stream()
-                .filter(Objects::nonNull)
                 .collect(Collectors.toMap(keyMapper, valueMapper));
     }
 
     public static <T, K, R> Map<K, R> collectToMap(
-            @NonNull Stream<T> items,
-            @NonNull Function<T, K> keyMapper,
-            @NonNull Function<T, R> valueMapper
+            Stream<@Nullable T> items,
+            Function<T, K> keyMapper,
+            Function<T, R> valueMapper
     ) {
         return items
                 .filter(Objects::nonNull)
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/util/FilterUtil.java b/src/main/java/it/aboutbits/springboot/toolbox/util/FilterUtil.java
index b61f5c3..15702f0 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/util/FilterUtil.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/util/FilterUtil.java
@@ -1,6 +1,6 @@
 package it.aboutbits.springboot.toolbox.util;
 
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 import org.springframework.data.util.Streamable;
 
 import java.util.Collection;
@@ -15,57 +15,58 @@
  * <p>
  * The returned collections are unmodifiable.
  */
+@NullMarked
 public final class FilterUtil {
     private FilterUtil() {
     }
 
-    public static <T> Set<T> filterToSet(@NonNull Collection<T> items, @NonNull Predicate<T> filter) {
+    public static <T> Set<T> filterToSet(Collection<T> items, Predicate<T> filter) {
         return items.stream()
                 .filter(filter)
                 .collect(Collectors.toUnmodifiableSet());
     }
 
-    public static <T> Set<T> filterToSet(@NonNull Streamable<T> items, @NonNull Predicate<T> filter) {
+    public static <T> Set<T> filterToSet(Streamable<T> items, Predicate<T> filter) {
         return items.stream()
                 .filter(filter)
                 .collect(Collectors.toUnmodifiableSet());
     }
 
-    public static <T> Set<T> filterToSet(@NonNull Stream<T> items, @NonNull Predicate<T> filter) {
+    public static <T> Set<T> filterToSet(Stream<T> items, Predicate<T> filter) {
         return items
                 .filter(filter)
                 .collect(Collectors.toUnmodifiableSet());
     }
 
-    public static <T> List<T> filterToList(@NonNull Collection<T> items, @NonNull Predicate<T> filter) {
+    public static <T> List<T> filterToList(Collection<T> items, Predicate<T> filter) {
         return items.stream()
                 .filter(filter)
                 .toList();
     }
 
-    public static <T> List<T> filterToList(@NonNull Streamable<T> items, @NonNull Predicate<T> filter) {
+    public static <T> List<T> filterToList(Streamable<T> items, Predicate<T> filter) {
         return items.stream()
                 .filter(filter)
                 .toList();
     }
 
-    public static <T> List<T> filterToList(@NonNull Stream<T> items, @NonNull Predicate<T> filter) {
+    public static <T> List<T> filterToList(Stream<T> items, Predicate<T> filter) {
         return items
                 .filter(filter)
                 .toList();
     }
 
-    public static <T> Stream<T> filterToStream(@NonNull Collection<T> items, @NonNull Predicate<T> filter) {
+    public static <T> Stream<T> filterToStream(Collection<T> items, Predicate<T> filter) {
         return items.stream()
                 .filter(filter);
     }
 
-    public static <T> Stream<T> filterToStream(@NonNull Streamable<T> items, @NonNull Predicate<T> filter) {
+    public static <T> Stream<T> filterToStream(Streamable<T> items, Predicate<T> filter) {
         return items.stream()
                 .filter(filter);
     }
 
-    public static <T> Stream<T> filterToStream(@NonNull Stream<T> items, @NonNull Predicate<T> filter) {
+    public static <T> Stream<T> filterToStream(Stream<T> items, Predicate<T> filter) {
         return items
                 .filter(filter);
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/util/NullableFunction.java b/src/main/java/it/aboutbits/springboot/toolbox/util/NullableFunction.java
new file mode 100644
index 0000000..9140462
--- /dev/null
+++ b/src/main/java/it/aboutbits/springboot/toolbox/util/NullableFunction.java
@@ -0,0 +1,10 @@
+package it.aboutbits.springboot.toolbox.util;
+
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+@NullMarked
+@FunctionalInterface
+public interface NullableFunction<T, R> {
+    @Nullable R apply(T t);
+}
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/validation/util/EmailAddressValidator.java b/src/main/java/it/aboutbits/springboot/toolbox/validation/util/EmailAddressValidator.java
index 62ed128..b9fc7dc 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/validation/util/EmailAddressValidator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/validation/util/EmailAddressValidator.java
@@ -1,7 +1,10 @@
 package it.aboutbits.springboot.toolbox.validation.util;
 
 import org.apache.commons.validator.routines.EmailValidator;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public final class EmailAddressValidator {
     private static final EmailValidator EMAIL_VALIDATOR = EmailValidator.getInstance();
 
@@ -14,14 +17,14 @@ private EmailAddressValidator() {
      * @param email the email address to validate
      * @return true if the email address is valid, false otherwise
      */
-    public static boolean isValid(String email) {
+    public static boolean isValid(@Nullable String email) {
         if (email == null) {
             return false;
         }
         return EMAIL_VALIDATOR.isValid(email);
     }
 
-    public static boolean isNotValid(String email) {
+    public static boolean isNotValid(@Nullable String email) {
         return !isValid(email);
     }
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/validation/util/IbanValidator.java b/src/main/java/it/aboutbits/springboot/toolbox/validation/util/IbanValidator.java
index b3de1a1..ea7a7bd 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/validation/util/IbanValidator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/validation/util/IbanValidator.java
@@ -1,7 +1,10 @@
 package it.aboutbits.springboot.toolbox.validation.util;
 
 import org.apache.commons.validator.routines.IBANValidator;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public final class IbanValidator {
     private static final IBANValidator IBAN_VALIDATOR = new IBANValidator();
 
@@ -14,14 +17,14 @@ private IbanValidator() {
      * @param iban the IBAN to be validated
      * @return true if the IBAN is valid, false otherwise
      */
-    public static boolean isValid(String iban) {
+    public static boolean isValid(@Nullable String iban) {
         if (iban == null) {
             return false;
         }
         return IBAN_VALIDATOR.isValid(iban);
     }
 
-    public static boolean isNotValid(String iban) {
+    public static boolean isNotValid(@Nullable String iban) {
         return !isValid(iban);
     }
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/MaxScaledBigDecimalValidator.java b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/MaxScaledBigDecimalValidator.java
index 024d124..1bdc7ad 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/MaxScaledBigDecimalValidator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/MaxScaledBigDecimalValidator.java
@@ -4,7 +4,10 @@
 import jakarta.validation.ConstraintValidator;
 import jakarta.validation.ConstraintValidatorContext;
 import jakarta.validation.constraints.Max;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public class MaxScaledBigDecimalValidator implements ConstraintValidator<Max, ScaledBigDecimal> {
 
     private long upperBound;
@@ -15,7 +18,7 @@ public void initialize(Max constraintAnnotation) {
     }
 
     @Override
-    public boolean isValid(ScaledBigDecimal scaledBigDecimal, ConstraintValidatorContext context) {
+    public boolean isValid(@Nullable ScaledBigDecimal scaledBigDecimal, ConstraintValidatorContext context) {
         if (scaledBigDecimal == null) {
             return true;
         }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/MinScaledBigDecimalValidator.java b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/MinScaledBigDecimalValidator.java
index 1cffd2a..18d50fc 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/MinScaledBigDecimalValidator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/MinScaledBigDecimalValidator.java
@@ -4,10 +4,13 @@
 import jakarta.validation.ConstraintValidator;
 import jakarta.validation.ConstraintValidatorContext;
 import jakarta.validation.constraints.Min;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public class MinScaledBigDecimalValidator implements ConstraintValidator<Min, ScaledBigDecimal> {
 
-    private Long lowerBound;
+    private @Nullable Long lowerBound;
 
     @Override
     public void initialize(Min constraintAnnotation) {
@@ -15,7 +18,11 @@ public void initialize(Min constraintAnnotation) {
     }
 
     @Override
-    public boolean isValid(ScaledBigDecimal scaledBigDecimal, ConstraintValidatorContext context) {
+    public boolean isValid(@Nullable ScaledBigDecimal scaledBigDecimal, ConstraintValidatorContext context) {
+        if (lowerBound == null) {
+            throw new IllegalStateException("lowerBound must be initialized");
+        }
+
         if (scaledBigDecimal == null) {
             return true;
         }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeOrZeroScaledBigDecimalValidator.java b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeOrZeroScaledBigDecimalValidator.java
index 31ac388..827f52d 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeOrZeroScaledBigDecimalValidator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeOrZeroScaledBigDecimalValidator.java
@@ -4,10 +4,13 @@
 import jakarta.validation.ConstraintValidator;
 import jakarta.validation.ConstraintValidatorContext;
 import jakarta.validation.constraints.NegativeOrZero;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public class NegativeOrZeroScaledBigDecimalValidator implements ConstraintValidator<NegativeOrZero, ScaledBigDecimal> {
     @Override
-    public boolean isValid(ScaledBigDecimal value, ConstraintValidatorContext context) {
+    public boolean isValid(@Nullable ScaledBigDecimal value, ConstraintValidatorContext context) {
         if (value == null) {
             return true;
         }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeScaledBigDecimalValidator.java b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeScaledBigDecimalValidator.java
index bdd3229..b4617fd 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeScaledBigDecimalValidator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeScaledBigDecimalValidator.java
@@ -4,10 +4,13 @@
 import jakarta.validation.ConstraintValidator;
 import jakarta.validation.ConstraintValidatorContext;
 import jakarta.validation.constraints.Negative;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public class NegativeScaledBigDecimalValidator implements ConstraintValidator<Negative, ScaledBigDecimal> {
     @Override
-    public boolean isValid(ScaledBigDecimal value, ConstraintValidatorContext context) {
+    public boolean isValid(@Nullable ScaledBigDecimal value, ConstraintValidatorContext context) {
         if (value == null) {
             return true;
         }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveOrZeroScaledBigDecimalValidator.java b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveOrZeroScaledBigDecimalValidator.java
index b1a0b85..a5c5b26 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveOrZeroScaledBigDecimalValidator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveOrZeroScaledBigDecimalValidator.java
@@ -4,10 +4,13 @@
 import jakarta.validation.ConstraintValidator;
 import jakarta.validation.ConstraintValidatorContext;
 import jakarta.validation.constraints.PositiveOrZero;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public class PositiveOrZeroScaledBigDecimalValidator implements ConstraintValidator<PositiveOrZero, ScaledBigDecimal> {
     @Override
-    public boolean isValid(ScaledBigDecimal value, ConstraintValidatorContext context) {
+    public boolean isValid(@Nullable ScaledBigDecimal value, ConstraintValidatorContext context) {
         if (value == null) {
             return true;
         }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveScaledBigDecimalValidator.java b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveScaledBigDecimalValidator.java
index 9202d83..c2a6e18 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveScaledBigDecimalValidator.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveScaledBigDecimalValidator.java
@@ -4,10 +4,13 @@
 import jakarta.validation.ConstraintValidator;
 import jakarta.validation.ConstraintValidatorContext;
 import jakarta.validation.constraints.Positive;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public class PositiveScaledBigDecimalValidator implements ConstraintValidator<Positive, ScaledBigDecimal> {
     @Override
-    public boolean isValid(ScaledBigDecimal value, ConstraintValidatorContext context) {
+    public boolean isValid(@Nullable ScaledBigDecimal value, ConstraintValidatorContext context) {
         if (value == null) {
             return true;
         }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/CustomTypePropertyEditor.java b/src/main/java/it/aboutbits/springboot/toolbox/web/CustomTypePropertyEditor.java
index a354853..45d9f5d 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/CustomTypePropertyEditor.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/CustomTypePropertyEditor.java
@@ -4,8 +4,8 @@
 import it.aboutbits.springboot.toolbox.reflection.util.CustomTypeReflectionUtil;
 import it.aboutbits.springboot.toolbox.type.CustomType;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
-import lombok.NonNull;
-import org.springframework.lang.Nullable;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.beans.PropertyEditorSupport;
 import java.lang.reflect.Constructor;
@@ -15,11 +15,12 @@
 import java.util.UUID;
 import java.util.function.Function;
 
+@NullMarked
 public final class CustomTypePropertyEditor<T extends CustomType<?>> extends PropertyEditorSupport {
     private final Constructor<T> constructor;
-    private final Function<String, Object> typeConverter;
+    private final Function<@Nullable String, @Nullable Object> typeConverter;
 
-    public CustomTypePropertyEditor(@NonNull Class<T> customType) {
+    public CustomTypePropertyEditor(Class<T> customType) {
         try {
             this.constructor = CustomTypeReflectionUtil.getCustomTypeConstructor(customType);
         } catch (NoSuchMethodException e) {
@@ -59,7 +60,7 @@ public void setAsText(String text) throws IllegalArgumentException {
         }
     }
 
-    private static Function<String, Object> getTextToTypeConverter(Class<?> wrappedType) {
+    private static Function<@Nullable String, @Nullable Object> getTextToTypeConverter(Class<?> wrappedType) {
         if (Boolean.class.isAssignableFrom(wrappedType)) {
             return Boolean::parseBoolean;
         }
@@ -75,34 +76,34 @@ private static Function<String, Object> getTextToTypeConverter(Class<?> wrappedT
             };
         }
         if (Byte.class.isAssignableFrom(wrappedType)) {
-            return Byte::parseByte;
+            return s -> s != null ? Byte.parseByte(s) : null;
         }
         if (Short.class.isAssignableFrom(wrappedType)) {
-            return Short::parseShort;
+            return s -> s != null ? Short.parseShort(s) : null;
         }
         if (Integer.class.isAssignableFrom(wrappedType)) {
-            return Integer::parseInt;
+            return s -> s != null ? Integer.parseInt(s) : null;
         }
         if (Long.class.isAssignableFrom(wrappedType)) {
-            return Long::parseLong;
+            return s -> s != null ? Long.parseLong(s) : null;
         }
         if (BigInteger.class.isAssignableFrom(wrappedType)) {
-            return BigInteger::new;
+            return val -> val != null ? new BigInteger(val) : null;
         }
         if (Float.class.isAssignableFrom(wrappedType)) {
-            return Float::parseFloat;
+            return s -> s != null ? Float.parseFloat(s) : null;
         }
         if (Double.class.isAssignableFrom(wrappedType)) {
-            return Double::parseDouble;
+            return s -> s != null ? Double.parseDouble(s) : null;
         }
         if (BigDecimal.class.isAssignableFrom(wrappedType)) {
-            return BigDecimal::new;
+            return val -> val != null ? new BigDecimal(val) : null;
         }
         if (ScaledBigDecimal.class.isAssignableFrom(wrappedType)) {
-            return ScaledBigDecimal::new;
+            return value -> value != null ? new ScaledBigDecimal(value) : null;
         }
         if (UUID.class.isAssignableFrom(wrappedType)) {
-            return UUID::fromString;
+            return name -> name != null ? UUID.fromString(name) : null;
         }
         if (Enum.class.isAssignableFrom(wrappedType)) {
             return toEnumConverter(wrappedType);
@@ -111,7 +112,7 @@ private static Function<String, Object> getTextToTypeConverter(Class<?> wrappedT
     }
 
     @SuppressWarnings("unchecked")
-    private static Function<String, Object> toEnumConverter(Class<?> wrappedType) {
+    private static Function<@Nullable String, @Nullable Object> toEnumConverter(Class<?> wrappedType) {
         var enumClass = (Class<? extends Enum<?>>) wrappedType.asSubclass(Enum.class);
 
         return text -> {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/EntityIdPropertyEditor.java b/src/main/java/it/aboutbits/springboot/toolbox/web/EntityIdPropertyEditor.java
index 8629715..3d7427f 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/EntityIdPropertyEditor.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/EntityIdPropertyEditor.java
@@ -1,10 +1,12 @@
 package it.aboutbits.springboot.toolbox.web;
 
 import it.aboutbits.springboot.toolbox.type.identity.EntityId;
-import org.springframework.lang.Nullable;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.beans.PropertyEditorSupport;
 
+@NullMarked
 public final class EntityIdPropertyEditor extends PropertyEditorSupport {
     @SuppressWarnings("unchecked")
     @Override
@@ -17,7 +19,7 @@ public String getAsText() {
 
     @Override
     public void setAsText(String text) throws IllegalArgumentException {
-        EntityId<?> value = null;
+        EntityId<?> value;
         try {
             var theValue = Long.parseLong(text);
             value = new EntityId<Long>() {
@@ -31,7 +33,7 @@ public String toString() {
                     return String.valueOf(value());
                 }
             };
-        } catch (NumberFormatException e) {
+        } catch (NumberFormatException _) {
             value = new EntityId<String>() {
                 @Override
                 public String value() {
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/SortParameterResolver.java b/src/main/java/it/aboutbits/springboot/toolbox/web/SortParameterResolver.java
index d63d186..6b2ebc2 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/SortParameterResolver.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/SortParameterResolver.java
@@ -1,7 +1,8 @@
 package it.aboutbits.springboot.toolbox.web;
 
 import it.aboutbits.springboot.toolbox.parameter.SortParameter;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springframework.core.MethodParameter;
 import org.springframework.web.bind.support.WebDataBinderFactory;
 import org.springframework.web.context.request.NativeWebRequest;
@@ -11,6 +12,7 @@
 import java.util.ArrayList;
 import java.util.Objects;
 
+@NullMarked
 public class SortParameterResolver implements HandlerMethodArgumentResolver {
     @Override
     public boolean supportsParameter(MethodParameter parameter) {
@@ -19,10 +21,10 @@ public boolean supportsParameter(MethodParameter parameter) {
 
     @Override
     public Object resolveArgument(
-            @NonNull MethodParameter parameter,
-            ModelAndViewContainer mavContainer,
+            MethodParameter parameter,
+            @Nullable ModelAndViewContainer mavContainer,
             NativeWebRequest webRequest,
-            WebDataBinderFactory binderFactory
+            @Nullable WebDataBinderFactory binderFactory
     ) throws IllegalArgumentException {
         var sorts = webRequest.getParameterValues(
                 Objects.requireNonNull(parameter.getParameterName())
@@ -64,7 +66,7 @@ public Object resolveArgument(
         return new SortParameter<>(sortFields);
     }
 
-    private org.springframework.data.domain.Sort.NullHandling nullHandlingFromString(@NonNull String value) {
+    private org.springframework.data.domain.Sort.NullHandling nullHandlingFromString(String value) {
         return switch (value.toLowerCase()) {
             case "first":
                 yield org.springframework.data.domain.Sort.NullHandling.NULLS_FIRST;
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ErrorResponse.java b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ErrorResponse.java
index 5481bcb..002dd2c 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ErrorResponse.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ErrorResponse.java
@@ -1,10 +1,12 @@
 package it.aboutbits.springboot.toolbox.web.response;
 
-import org.springframework.lang.Nullable;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.util.List;
 import java.util.Map;
 
+@NullMarked
 public record ErrorResponse(
         @Nullable String message,
         @Nullable Map<String, List<String>> errors
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ItemResponse.java b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ItemResponse.java
index bd1ce58..56f7af4 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ItemResponse.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ItemResponse.java
@@ -1,10 +1,11 @@
 package it.aboutbits.springboot.toolbox.web.response;
 
 import it.aboutbits.springboot.toolbox.web.response.meta.Meta;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class ItemResponse<T> extends ItemResponseWithMeta<T, Meta.EmptyMeta> {
-    public ItemResponse(@NonNull T data) {
+    public ItemResponse(T data) {
         super(data, new Meta.EmptyMeta());
     }
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ItemResponseWithMeta.java b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ItemResponseWithMeta.java
index 27d3d1d..2ace582 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ItemResponseWithMeta.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ItemResponseWithMeta.java
@@ -3,15 +3,16 @@
 import it.aboutbits.springboot.toolbox.web.response.meta.Meta;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @EqualsAndHashCode
+@NullMarked
 public class ItemResponseWithMeta<T, M extends Meta> {
     private final T data;
     private final M meta;
 
-    public ItemResponseWithMeta(@NonNull T data, @NonNull M meta) {
+    public ItemResponseWithMeta(T data, M meta) {
         this.data = data;
         this.meta = meta;
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ListResponse.java b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ListResponse.java
index 010e11c..0d2a61e 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ListResponse.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ListResponse.java
@@ -1,12 +1,13 @@
 package it.aboutbits.springboot.toolbox.web.response;
 
 import it.aboutbits.springboot.toolbox.web.response.meta.Meta;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 
 import java.util.List;
 
+@NullMarked
 public final class ListResponse<T> extends ListResponseWithMeta<T, Meta.EmptyMeta> {
-    public ListResponse(@NonNull List<T> data) {
+    public ListResponse(List<T> data) {
         super(data, new Meta.EmptyMeta());
     }
 }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ListResponseWithMeta.java b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ListResponseWithMeta.java
index 5defa29..eb8b53c 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/response/ListResponseWithMeta.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/response/ListResponseWithMeta.java
@@ -3,17 +3,18 @@
 import it.aboutbits.springboot.toolbox.web.response.meta.Meta;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 
 import java.util.List;
 
 @Getter
 @EqualsAndHashCode
+@NullMarked
 public class ListResponseWithMeta<T, M extends Meta> {
     private final List<T> data;
     private final M meta;
 
-    public ListResponseWithMeta(@NonNull List<T> data, @NonNull M meta) {
+    public ListResponseWithMeta(List<T> data, M meta) {
         this.data = data;
         this.meta = meta;
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/response/PagedResponse.java b/src/main/java/it/aboutbits/springboot/toolbox/web/response/PagedResponse.java
index 3bf2305..9779176 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/response/PagedResponse.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/response/PagedResponse.java
@@ -1,26 +1,27 @@
 package it.aboutbits.springboot.toolbox.web.response;
 
 import it.aboutbits.springboot.toolbox.web.response.meta.MetaWithPagination;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 import org.springframework.data.domain.Page;
 
 import java.util.List;
 import java.util.function.Function;
 
+@NullMarked
 public final class PagedResponse<T> extends PagedResponseWithMeta<T, MetaWithPagination> {
 
-    public PagedResponse(@NonNull List<T> data, @NonNull MetaWithPagination meta) {
+    public PagedResponse(List<T> data, MetaWithPagination meta) {
         super(data, meta);
     }
 
-    public static <T> PagedResponse<T> of(@NonNull Page<T> page) {
+    public static <T> PagedResponse<T> of(Page<T> page) {
         return new PagedResponse<>(
                 page.getContent(),
                 MetaWithPagination.of(page)
         );
     }
 
-    public static <I, O> PagedResponse<O> of(@NonNull Page<I> page, @NonNull Function<I, O> converter) {
+    public static <I, O> PagedResponse<O> of(Page<I> page, Function<I, O> converter) {
         var mapped = page.map(converter);
 
         return new PagedResponse<>(
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/response/PagedResponseWithMeta.java b/src/main/java/it/aboutbits/springboot/toolbox/web/response/PagedResponseWithMeta.java
index 7675ee1..b51f49c 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/response/PagedResponseWithMeta.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/response/PagedResponseWithMeta.java
@@ -3,17 +3,18 @@
 import it.aboutbits.springboot.toolbox.web.response.meta.MetaWithPagination;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 
 import java.util.List;
 
 @Getter
 @EqualsAndHashCode
+@NullMarked
 public class PagedResponseWithMeta<T, M extends MetaWithPagination> {
     private final List<T> data;
     private final M meta;
 
-    public PagedResponseWithMeta(@NonNull List<T> data, @NonNull M meta) {
+    public PagedResponseWithMeta(List<T> data, M meta) {
         this.data = data;
         this.meta = meta;
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/response/meta/Meta.java b/src/main/java/it/aboutbits/springboot/toolbox/web/response/meta/Meta.java
index c9bd1ca..85fa323 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/response/meta/Meta.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/response/meta/Meta.java
@@ -1,5 +1,8 @@
 package it.aboutbits.springboot.toolbox.web.response.meta;
 
+import org.jspecify.annotations.NullMarked;
+
+@NullMarked
 public interface Meta {
     record EmptyMeta() implements Meta {
     }
diff --git a/src/main/java/it/aboutbits/springboot/toolbox/web/response/meta/MetaWithPagination.java b/src/main/java/it/aboutbits/springboot/toolbox/web/response/meta/MetaWithPagination.java
index 5280d6b..315c375 100644
--- a/src/main/java/it/aboutbits/springboot/toolbox/web/response/meta/MetaWithPagination.java
+++ b/src/main/java/it/aboutbits/springboot/toolbox/web/response/meta/MetaWithPagination.java
@@ -2,15 +2,16 @@
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 import org.springframework.data.domain.Page;
 
 @Getter
 @EqualsAndHashCode
+@NullMarked
 public class MetaWithPagination implements Meta {
     private final Pagination pagination;
 
-    public MetaWithPagination(@NonNull Pagination pagination) {
+    public MetaWithPagination(Pagination pagination) {
         this.pagination = pagination;
     }
 
@@ -18,7 +19,7 @@ public Pagination pagination() {
         return pagination;
     }
 
-    public static MetaWithPagination of(@NonNull Page<?> page) {
+    public static MetaWithPagination of(Page<?> page) {
         return new MetaWithPagination(
                 new MetaWithPagination.Pagination(
                         page.getNumber(),
@@ -29,7 +30,7 @@ public static MetaWithPagination of(@NonNull Page<?> page) {
     }
 
     public record Pagination(long page, int size, long totalElements) {
-        public static Pagination of(@NonNull Page<?> page) {
+        public static Pagination of(Page<?> page) {
             return new Pagination(
                     page.getNumber(),
                     page.getSize(),
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/ArchitectureTest.java b/src/test/java/it/aboutbits/springboot/toolbox/ArchitectureTest.java
new file mode 100644
index 0000000..d1988b1
--- /dev/null
+++ b/src/test/java/it/aboutbits/springboot/toolbox/ArchitectureTest.java
@@ -0,0 +1,15 @@
+package it.aboutbits.springboot.toolbox;
+
+import com.tngtech.archunit.junit.AnalyzeClasses;
+import com.tngtech.archunit.junit.CacheMode;
+import it.aboutbits.archunit.toolbox.ArchitectureTestBase;
+import org.jspecify.annotations.NullMarked;
+
+@AnalyzeClasses(
+        packages = ArchitectureTest.PACKAGE,
+        cacheMode = CacheMode.PER_CLASS
+)
+@NullMarked
+class ArchitectureTest extends ArchitectureTestBase {
+    static final String PACKAGE = "it.aboutbits.springboot.toolbox";
+}
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/TestApp.java b/src/test/java/it/aboutbits/springboot/toolbox/TestApp.java
index 0ebacc0..f973635 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/TestApp.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/TestApp.java
@@ -1,16 +1,16 @@
 package it.aboutbits.springboot.toolbox;
 
 import it.aboutbits.springboot.toolbox.autoconfiguration.web.RegisterCustomTypesWithJacksonAndMvc;
+import org.jspecify.annotations.NullMarked;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
 @SuppressWarnings("checkstyle:HideUtilityClassConstructor")
 @SpringBootApplication
 @RegisterCustomTypesWithJacksonAndMvc
+@NullMarked
 public class TestApp {
-
-    public static void main(String[] args) {
+    static void main(String[] args) {
         SpringApplication.run(TestApp.class, args);
     }
-
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/_support/ApplicationTest.java b/src/test/java/it/aboutbits/springboot/toolbox/_support/ApplicationTest.java
index 3c1a7f8..ee909f9 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/_support/ApplicationTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/_support/ApplicationTest.java
@@ -1,6 +1,7 @@
 package it.aboutbits.springboot.toolbox._support;
 
 import it.aboutbits.springboot.toolbox._support.persistence.WithPostgres;
+import org.jspecify.annotations.NullMarked;
 import org.springframework.boot.test.context.SpringBootTest;
 
 import java.lang.annotation.ElementType;
@@ -12,6 +13,7 @@
 @Retention(RetentionPolicy.RUNTIME)
 @SpringBootTest
 @WithPostgres
+@NullMarked
 public @interface ApplicationTest {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/_support/HttpTest.java b/src/test/java/it/aboutbits/springboot/toolbox/_support/HttpTest.java
index 30c0520..20040f1 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/_support/HttpTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/_support/HttpTest.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox._support;
 
+import org.jspecify.annotations.NullMarked;
 import org.springframework.boot.webmvc.test.autoconfigure.AutoConfigureMockMvc;
 
 import java.lang.annotation.Retention;
@@ -8,6 +9,7 @@
 @Retention(RetentionPolicy.RUNTIME)
 @ApplicationTest
 @AutoConfigureMockMvc
+@NullMarked
 public @interface HttpTest {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/_support/WithPersistence.java b/src/test/java/it/aboutbits/springboot/toolbox/_support/WithPersistence.java
index 3dedf8e..6e42a87 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/_support/WithPersistence.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/_support/WithPersistence.java
@@ -1,12 +1,14 @@
 package it.aboutbits.springboot.toolbox._support;
 
 import it.aboutbits.springboot.toolbox._support.persistence.WithPostgres;
+import org.jspecify.annotations.NullMarked;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
 @Retention(RetentionPolicy.RUNTIME)
 @WithPostgres
+@NullMarked
 public @interface WithPersistence {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/_support/persistence/PostgresTestcontainer.java b/src/test/java/it/aboutbits/springboot/toolbox/_support/persistence/PostgresTestcontainer.java
index e2b9b43..91ed7c5 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/_support/persistence/PostgresTestcontainer.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/_support/persistence/PostgresTestcontainer.java
@@ -1,10 +1,11 @@
 package it.aboutbits.springboot.toolbox._support.persistence;
 
-import lombok.extern.log4j.Log4j2;
+import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.extension.AfterEachCallback;
 import org.junit.jupiter.api.extension.BeforeAllCallback;
 import org.junit.jupiter.api.extension.ExtensionContext;
-import org.testcontainers.containers.PostgreSQLContainer;
+import org.testcontainers.postgresql.PostgreSQLContainer;
 import org.testcontainers.utility.DockerImageName;
 
 import java.sql.Connection;
@@ -15,9 +16,10 @@
 import java.util.Set;
 import java.util.StringJoiner;
 
-@Log4j2
+@Slf4j
+@NullMarked
 public class PostgresTestcontainer implements BeforeAllCallback, AfterEachCallback {
-    public static final PostgreSQLContainer<?> POSTGRES_CONTAINER;
+    public static final PostgreSQLContainer POSTGRES_CONTAINER;
     private static final Set<String> TABLES_TO_IGNORE = Set.of(
             "databasechangelog",
             "databasechangeloglock"
@@ -25,7 +27,7 @@ public class PostgresTestcontainer implements BeforeAllCallback, AfterEachCallba
 
     // See https://www.postgresql.org/docs/current/non-durability.html for details about PostgreSQL CLI parameters
     static {
-        POSTGRES_CONTAINER = new PostgreSQLContainer<>(
+        POSTGRES_CONTAINER = new PostgreSQLContainer(
                 DockerImageName.parse("postgres:16").asCompatibleSubstituteFor("postgres"))
                 .withDatabaseName("app")
                 .withCommand(
@@ -62,7 +64,7 @@ public void afterEach(ExtensionContext extensionContext) throws Exception {
             cleanTablesData(tablesToClean, connection);
             connection.commit();
         } catch (SQLException exception) {
-            exception.printStackTrace();
+            log.error("Error cleaning database", exception);
         }
     }
 
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/_support/persistence/WithPostgres.java b/src/test/java/it/aboutbits/springboot/toolbox/_support/persistence/WithPostgres.java
index be92a4a..4a04dd3 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/_support/persistence/WithPostgres.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/_support/persistence/WithPostgres.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox._support.persistence;
 
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.jupiter.api.parallel.ResourceAccessMode;
 import org.junit.jupiter.api.parallel.ResourceLock;
@@ -10,5 +11,6 @@
 @Retention(RetentionPolicy.RUNTIME)
 @ExtendWith({PostgresTestcontainer.class})
 @ResourceLock(value = "Database", mode = ResourceAccessMode.READ_WRITE)
+@NullMarked
 public @interface WithPostgres {
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/CustomTypeBindingsForControllerTest.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/CustomTypeBindingsForControllerTest.java
index b3c0c73..c264c28 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/CustomTypeBindingsForControllerTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/CustomTypeBindingsForControllerTest.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.mvc;
 
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreNoProductionCounterpart;
 import it.aboutbits.springboot.toolbox._support.HttpTest;
 import it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body.BodyWithEmailAddress;
 import it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body.BodyWithIban;
@@ -8,7 +9,7 @@
 import it.aboutbits.springboot.toolbox.type.EmailAddress;
 import it.aboutbits.springboot.toolbox.type.Iban;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -23,8 +24,10 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@ArchIgnoreNoProductionCounterpart
 @HttpTest
-public class CustomTypeBindingsForControllerTest {
+@NullMarked
+class CustomTypeBindingsForControllerTest {
     @Autowired
     protected MockMvc mockMvc;
 
@@ -217,7 +220,7 @@ void UUIDAsBody(String uuidStringValue) throws Exception {
         }
     }
 
-    private @NonNull String performGetAndReturnResult(@NonNull String url) throws Exception {
+    private String performGetAndReturnResult(String url) throws Exception {
         var requestBuilder = MockMvcRequestBuilders.get(url)
                 .contentType(MediaType.APPLICATION_JSON);
 
@@ -227,7 +230,7 @@ void UUIDAsBody(String uuidStringValue) throws Exception {
                 .getContentAsString();
     }
 
-    private @NonNull String performPostAndReturnResult(@NonNull String url, @NonNull Object body) throws Exception {
+    private String performPostAndReturnResult(String url, Object body) throws Exception {
         var requestBuilder = MockMvcRequestBuilders.post(url)
                 .content(jsonMapper.writeValueAsString(body))
                 .contentType(MediaType.APPLICATION_JSON);
@@ -237,5 +240,4 @@ void UUIDAsBody(String uuidStringValue) throws Exception {
                 .getResponse()
                 .getContentAsString();
     }
-
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/EntityIdBindingsForControllerTest.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/EntityIdBindingsForControllerTest.java
index e2213d3..9af44d6 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/EntityIdBindingsForControllerTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/EntityIdBindingsForControllerTest.java
@@ -1,11 +1,12 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.mvc;
 
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreNoProductionCounterpart;
 import it.aboutbits.springboot.toolbox._support.HttpTest;
 import it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body.BodyWithEntityId;
 import it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body.BodyWithEnumEntityId;
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeEnumTestModel;
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeTestModel;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -16,8 +17,10 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@ArchIgnoreNoProductionCounterpart
 @HttpTest
-public class EntityIdBindingsForControllerTest {
+@NullMarked
+class EntityIdBindingsForControllerTest {
     @Autowired
     protected MockMvc mockMvc;
 
@@ -114,7 +117,7 @@ void emailAddressAsBody() throws Exception {
         }
     }
 
-    private @NonNull String performGetAndReturnResult(@NonNull String url) throws Exception {
+    private String performGetAndReturnResult(String url) throws Exception {
         var requestBuilder = MockMvcRequestBuilders.get(url)
                 .contentType(MediaType.APPLICATION_JSON);
 
@@ -124,7 +127,7 @@ void emailAddressAsBody() throws Exception {
                 .getContentAsString();
     }
 
-    private @NonNull String performPostAndReturnResult(@NonNull String url, @NonNull Object body) throws Exception {
+    private String performPostAndReturnResult(String url, Object body) throws Exception {
         var requestBuilder = MockMvcRequestBuilders.post(url)
                 .content(jsonMapper.writeValueAsString(body))
                 .contentType(MediaType.APPLICATION_JSON);
@@ -134,5 +137,4 @@ void emailAddressAsBody() throws Exception {
                 .getResponse()
                 .getContentAsString();
     }
-
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEmailAddress.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEmailAddress.java
index 6feb6ff..2ec0f06 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEmailAddress.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEmailAddress.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body;
 
 import it.aboutbits.springboot.toolbox.type.EmailAddress;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record BodyWithEmailAddress(
         EmailAddress emailAddress
 ) {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEntityId.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEntityId.java
index 5a75d33..6800623 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEntityId.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEntityId.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body;
 
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeTestModel;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record BodyWithEntityId(
         CustomTypeTestModel.ID entityId
 ) {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEnumEntityId.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEnumEntityId.java
index 8ffba20..2330c62 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEnumEntityId.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithEnumEntityId.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body;
 
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeEnumTestModel;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record BodyWithEnumEntityId(
         CustomTypeEnumTestModel.ID enumEntityId
 ) {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithIban.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithIban.java
index 607e29f..132dd8e 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithIban.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithIban.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body;
 
 import it.aboutbits.springboot.toolbox.type.Iban;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record BodyWithIban(
         Iban iban
 ) {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithScaledBigDecimal.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithScaledBigDecimal.java
index e2c9cea..290820e 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithScaledBigDecimal.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithScaledBigDecimal.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body;
 
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record BodyWithScaledBigDecimal(
         ScaledBigDecimal scaledBigDecimal
 ) {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithUUID.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithUUID.java
index d6f2a1d..fd52d1e 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithUUID.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/body/BodyWithUUID.java
@@ -1,7 +1,10 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body;
 
+import org.jspecify.annotations.NullMarked;
+
 import java.util.UUID;
 
+@NullMarked
 public record BodyWithUUID(
         UUID uuid
 ) {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/controller/CustomTypeTestController.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/controller/CustomTypeTestController.java
index 4551cff..8373216 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/controller/CustomTypeTestController.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/controller/CustomTypeTestController.java
@@ -7,6 +7,7 @@
 import it.aboutbits.springboot.toolbox.type.EmailAddress;
 import it.aboutbits.springboot.toolbox.type.Iban;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import org.jspecify.annotations.NullMarked;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
@@ -19,6 +20,7 @@
 
 @RestController
 @RequestMapping("/test/type")
+@NullMarked
 public class CustomTypeTestController {
     @GetMapping("/EmailAddress/as-path-variable/{value}")
     public EmailAddress emailAddressAsPathVariable(@PathVariable EmailAddress value) {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/controller/EntityIdTestController.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/controller/EntityIdTestController.java
index 0cdc542..38d87de 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/controller/EntityIdTestController.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/mvc/controller/EntityIdTestController.java
@@ -4,6 +4,7 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.mvc.body.BodyWithEnumEntityId;
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeEnumTestModel;
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeTestModel;
+import org.jspecify.annotations.NullMarked;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
@@ -14,6 +15,7 @@
 
 @RestController
 @RequestMapping("/test/entity-id")
+@NullMarked
 public class EntityIdTestController {
     @GetMapping("/CustomTypeTestModel.ID/as-path-variable/{value}")
     public CustomTypeTestModel.ID customTypeTestModelIdAsPathVariable(@PathVariable CustomTypeTestModel.ID value) {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/CustomTypeJpaTest.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/CustomTypeJpaTest.java
index 3dc2854..cab75dd 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/CustomTypeJpaTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/CustomTypeJpaTest.java
@@ -1,11 +1,13 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.persistence;
 
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreNoProductionCounterpart;
 import it.aboutbits.springboot.toolbox._support.ApplicationTest;
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeTestModel;
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeTestModelRepository;
 import it.aboutbits.springboot.toolbox.type.EmailAddress;
 import it.aboutbits.springboot.toolbox.type.Iban;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -16,8 +18,10 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@ArchIgnoreNoProductionCounterpart
 @ApplicationTest
-public class CustomTypeJpaTest {
+@NullMarked
+class CustomTypeJpaTest {
     @Autowired
     CustomTypeTestModelRepository repository;
 
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/EntityIdJpaTest.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/EntityIdJpaTest.java
index fb214cb..cc51eaf 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/EntityIdJpaTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/EntityIdJpaTest.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.persistence;
 
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreNoProductionCounterpart;
 import it.aboutbits.springboot.toolbox._support.ApplicationTest;
 import it.aboutbits.springboot.toolbox._support.WithPersistence;
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeEnumTestModel;
@@ -7,6 +8,7 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeTestModel;
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.CustomTypeTestModelRepository;
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa.ReferencedTestModel;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -15,9 +17,11 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@ArchIgnoreNoProductionCounterpart
 @ApplicationTest
 @WithPersistence
-public class EntityIdJpaTest {
+@NullMarked
+class EntityIdJpaTest {
     @Autowired
     CustomTypeTestModelRepository repository;
 
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeEnumTestModel.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeEnumTestModel.java
index 3ddf7ee..da9792b 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeEnumTestModel.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeEnumTestModel.java
@@ -10,12 +10,16 @@
 import lombok.Getter;
 import lombok.Setter;
 import org.hibernate.annotations.JavaType;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.NullUnmarked;
 
 @Entity
 @Getter
 @Setter
 @Table(name = "custom_type_enum_test_model")
-public class CustomTypeEnumTestModel implements Identified<CustomTypeEnumTestModel.ID> {
+@NullUnmarked
+public class CustomTypeEnumTestModel implements Identified<CustomTypeEnumTestModel.@NonNull ID> {
     @Id
     @JavaType(CustomTypeEnumTestModel.ID.JavaType.class)
     private ID id;
@@ -24,6 +28,7 @@ public enum CustomTypeEnum {
         ENUM_FIRST, ENUM_OTHER, ENUM_LAST
     }
 
+    @NullMarked
     public record ID(
             CustomTypeEnum value
     ) implements EntityId<CustomTypeEnum> {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeEnumTestModelRepository.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeEnumTestModelRepository.java
index eb2fb33..6af4d17 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeEnumTestModelRepository.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeEnumTestModelRepository.java
@@ -1,6 +1,8 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.persistence.impl.jpa;
 
+import org.jspecify.annotations.NullMarked;
 import org.springframework.data.jpa.repository.JpaRepository;
 
+@NullMarked
 public interface CustomTypeEnumTestModelRepository extends JpaRepository<CustomTypeEnumTestModel, CustomTypeEnumTestModel.ID> {
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeTestModel.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeTestModel.java
index 49b80b1..8203223 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeTestModel.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeTestModel.java
@@ -20,6 +20,9 @@
 import lombok.Getter;
 import lombok.Setter;
 import org.hibernate.annotations.JavaType;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.NullUnmarked;
 
 import java.util.UUID;
 
@@ -27,7 +30,8 @@
 @Getter
 @Setter
 @Table(name = "custom_type_test_model")
-public class CustomTypeTestModel implements Identified<CustomTypeTestModel.ID> {
+@NullUnmarked
+public class CustomTypeTestModel implements Identified<CustomTypeTestModel.@NonNull ID> {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     @JavaType(CustomTypeTestModel.ID.JavaType.class)
@@ -53,6 +57,7 @@ public class CustomTypeTestModel implements Identified<CustomTypeTestModel.ID> {
     @JavaType(ReferencedTestModel.ID.JavaType.class)
     private ReferencedTestModel.ID referencedId;
 
+    @NullMarked
     public record ID(
             Long value
     ) implements EntityId<Long> {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeTestModelRepository.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeTestModelRepository.java
index bbd6270..a589bee 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeTestModelRepository.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/CustomTypeTestModelRepository.java
@@ -3,11 +3,13 @@
 import it.aboutbits.springboot.toolbox.type.EmailAddress;
 import it.aboutbits.springboot.toolbox.type.Iban;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import org.jspecify.annotations.NullMarked;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import java.util.Optional;
 import java.util.UUID;
 
+@NullMarked
 public interface CustomTypeTestModelRepository extends JpaRepository<CustomTypeTestModel, CustomTypeTestModel.ID> {
     Optional<CustomTypeTestModel> findByEmail(EmailAddress emailAddress);
 
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/ReferencedTestModel.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/ReferencedTestModel.java
index 9c646bc..130b8c1 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/ReferencedTestModel.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/persistence/impl/jpa/ReferencedTestModel.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedLongJavaType;
 import it.aboutbits.springboot.toolbox.type.identity.EntityId;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public class ReferencedTestModel {
     // we just use this to have and ID we can actually reference
 
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/swagger/SwaggerTest.java b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/swagger/SwaggerTest.java
index ca25e28..d221ec5 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/swagger/SwaggerTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/autoconfiguration/swagger/SwaggerTest.java
@@ -1,7 +1,8 @@
 package it.aboutbits.springboot.toolbox.autoconfiguration.swagger;
 
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreNoProductionCounterpart;
 import it.aboutbits.springboot.toolbox._support.HttpTest;
-import lombok.NonNull;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.MediaType;
@@ -10,8 +11,10 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@ArchIgnoreNoProductionCounterpart
 @HttpTest
-public class SwaggerTest {
+@NullMarked
+class SwaggerTest {
     @Autowired
     MockMvc mockMvc;
 
@@ -24,7 +27,7 @@ void shouldBeAccessible() throws Exception {
         assertThat(swaggerSchemaString).isNotBlank();
     }
 
-    private @NonNull String performGetAndReturnResult(@NonNull String url) throws Exception {
+    private String performGetAndReturnResult(String url) throws Exception {
         var requestBuilder = MockMvcRequestBuilders.get(url)
                 .contentType(MediaType.APPLICATION_JSON);
 
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/parameter/SortParameterTest.java b/src/test/java/it/aboutbits/springboot/toolbox/parameter/SortParameterTest.java
index 9307540..74e463f 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/parameter/SortParameterTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/parameter/SortParameterTest.java
@@ -1,6 +1,7 @@
 package it.aboutbits.springboot.toolbox.parameter;
 
 import it.aboutbits.springboot.toolbox.persistence.SortMappings;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.springframework.data.domain.Sort;
@@ -11,6 +12,7 @@
 import static it.aboutbits.springboot.toolbox.persistence.SortMappings.map;
 import static org.assertj.core.api.Assertions.assertThat;
 
+@NullMarked
 class SortParameterTest {
     @SuppressWarnings("java:S115")
     private enum ESort implements SortParameter.Definition {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/WrapperTypesJpaTest.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/WrapperTypesJpaTest.java
index 15360ad..58cabe9 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/WrapperTypesJpaTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/WrapperTypesJpaTest.java
@@ -1,5 +1,7 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype;
 
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreGroupName;
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreNoProductionCounterpart;
 import it.aboutbits.springboot.toolbox._support.ApplicationTest;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.jpa.WrapperTypesModel;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.jpa.WrapperTypesModelRepository;
@@ -33,6 +35,7 @@
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapUUIDClass;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapUUIDRecord;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -46,14 +49,17 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@ArchIgnoreNoProductionCounterpart
 @ApplicationTest
-public class WrapperTypesJpaTest {
+@NullMarked
+class WrapperTypesJpaTest {
     @Autowired
     WrapperTypesModelRepository repository;
 
     @Nested
     class RecordTypes {
         @Nested
+        @ArchIgnoreGroupName
         class WrapBigDecimalRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -88,6 +94,7 @@ void givenValues_inAndOut_shouldSucceed(double doubleValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapBigIntegerRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -122,6 +129,7 @@ void givenValues_inAndOut_shouldSucceed(int intValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapDoubleRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -156,6 +164,7 @@ void givenValues_inAndOut_shouldSucceed(double doubleValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapFloatRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -190,6 +199,7 @@ void givenValues_inAndOut_shouldSucceed(float floatValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapIntegerRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -224,6 +234,7 @@ void givenValues_inAndOut_shouldSucceed(int intValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapLongRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -258,6 +269,7 @@ void givenValues_inAndOut_shouldSucceed(long longValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapScaledBigDecimalRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -292,6 +304,7 @@ void givenValues_inAndOut_shouldSucceed(double doubleValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapShortRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -326,6 +339,7 @@ void givenValues_inAndOut_shouldSucceed(short shortValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapStringRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -360,6 +374,7 @@ void givenValues_inAndOut_shouldSucceed(String stringValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapCharacterRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -394,6 +409,7 @@ void givenValues_inAndOut_shouldSucceed(Character charValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapByteRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -428,6 +444,7 @@ void givenValues_inAndOut_shouldSucceed(Byte byteValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapBooleanRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -462,6 +479,7 @@ void givenValues_inAndOut_shouldSucceed(Boolean boolValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapUUIDRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -527,6 +545,7 @@ void givenStringValues_inAndOut_shouldSucceed(String uuidStringValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapEnumRecordType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -564,6 +583,7 @@ void givenValues_inAndOut_shouldSucceed(SampleEnum enumValue) {
     @Nested
     class ClassTypes {
         @Nested
+        @ArchIgnoreGroupName
         class WrapBigDecimalClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -598,6 +618,7 @@ void givenValues_inAndOut_shouldSucceed(double doubleValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapBigIntegerClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -632,6 +653,7 @@ void givenValues_inAndOut_shouldSucceed(int intValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapDoubleClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -666,6 +688,7 @@ void givenValues_inAndOut_shouldSucceed(double doubleValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapFloatClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -700,6 +723,7 @@ void givenValues_inAndOut_shouldSucceed(float floatValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapIntegerClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -734,6 +758,7 @@ void givenValues_inAndOut_shouldSucceed(int intValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapLongClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -768,6 +793,7 @@ void givenValues_inAndOut_shouldSucceed(long longValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapScaledBigDecimalClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -802,6 +828,7 @@ void givenValues_inAndOut_shouldSucceed(double doubleValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapShortClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -836,6 +863,7 @@ void givenValues_inAndOut_shouldSucceed(short shortValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapStringClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -870,6 +898,7 @@ void givenValues_inAndOut_shouldSucceed(String stringValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapCharacterClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -904,6 +933,7 @@ void givenValues_inAndOut_shouldSucceed(Character charValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapByteClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -938,6 +968,7 @@ void givenValues_inAndOut_shouldSucceed(Byte byteValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapBooleanClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -972,6 +1003,7 @@ void givenValues_inAndOut_shouldSucceed(Boolean boolValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapUUIDClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
@@ -1037,6 +1069,7 @@ void givenStringValues_inAndOut_shouldSucceed(String uuidStringValue) {
         }
 
         @Nested
+        @ArchIgnoreGroupName
         class WrapEnumClassType {
             @Test
             void givenNull_inAndOut_shouldSucceed() {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigDecimalClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigDecimalClassJavaType.java
index ec5b845..b4d757c 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigDecimalClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigDecimalClassJavaType.java
@@ -3,6 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedBigDecimalJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapBigDecimalClass;
+import org.jspecify.annotations.NullMarked;
+
+@NullMarked
 
 public final class WrapBigDecimalClassJavaType extends WrappedBigDecimalJavaType<WrapBigDecimalClass> implements AutoRegisteredJavaType<WrapBigDecimalClass> {
     public WrapBigDecimalClassJavaType() {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigDecimalRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigDecimalRecordJavaType.java
index 65bd53c..e323234 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigDecimalRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigDecimalRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedBigDecimalJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapBigDecimalRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapBigDecimalRecordJavaType extends WrappedBigDecimalJavaType<WrapBigDecimalRecord> implements AutoRegisteredJavaType<WrapBigDecimalRecord> {
     public WrapBigDecimalRecordJavaType() {
         super(WrapBigDecimalRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigIntegerClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigIntegerClassJavaType.java
index 708dbb7..cec43cf 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigIntegerClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigIntegerClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedBigIntegerJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapBigIntegerClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapBigIntegerClassJavaType extends WrappedBigIntegerJavaType<WrapBigIntegerClass> implements AutoRegisteredJavaType<WrapBigIntegerClass> {
     public WrapBigIntegerClassJavaType() {
         super(WrapBigIntegerClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigIntegerRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigIntegerRecordJavaType.java
index 95a7396..e3967ef 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigIntegerRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBigIntegerRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedBigIntegerJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapBigIntegerRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapBigIntegerRecordJavaType extends WrappedBigIntegerJavaType<WrapBigIntegerRecord> implements AutoRegisteredJavaType<WrapBigIntegerRecord> {
     public WrapBigIntegerRecordJavaType() {
         super(WrapBigIntegerRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBooleanClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBooleanClassJavaType.java
index a2af7fa..71e9d3b 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBooleanClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBooleanClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedBooleanJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapBooleanClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapBooleanClassJavaType extends WrappedBooleanJavaType<WrapBooleanClass> implements AutoRegisteredJavaType<WrapBooleanClass> {
     public WrapBooleanClassJavaType() {
         super(WrapBooleanClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBooleanRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBooleanRecordJavaType.java
index 3514fc7..d1d5951 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBooleanRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapBooleanRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedBooleanJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapBooleanRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapBooleanRecordJavaType extends WrappedBooleanJavaType<WrapBooleanRecord> implements AutoRegisteredJavaType<WrapBooleanRecord> {
     public WrapBooleanRecordJavaType() {
         super(WrapBooleanRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapByteClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapByteClassJavaType.java
index 987f4bb..bf7db7c 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapByteClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapByteClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedByteJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapByteClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapByteClassJavaType extends WrappedByteJavaType<WrapByteClass> implements AutoRegisteredJavaType<WrapByteClass> {
     public WrapByteClassJavaType() {
         super(WrapByteClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapByteRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapByteRecordJavaType.java
index ce2992c..8330f2c 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapByteRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapByteRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedByteJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapByteRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapByteRecordJavaType extends WrappedByteJavaType<WrapByteRecord> implements AutoRegisteredJavaType<WrapByteRecord> {
     public WrapByteRecordJavaType() {
         super(WrapByteRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapCharacterClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapCharacterClassJavaType.java
index d83cccc..f8e5683 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapCharacterClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapCharacterClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedCharacterJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapCharacterClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapCharacterClassJavaType extends WrappedCharacterJavaType<WrapCharacterClass> implements AutoRegisteredJavaType<WrapCharacterClass> {
     public WrapCharacterClassJavaType() {
         super(WrapCharacterClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapCharacterRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapCharacterRecordJavaType.java
index b044f46..21b32a7 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapCharacterRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapCharacterRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedCharacterJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapCharacterRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapCharacterRecordJavaType extends WrappedCharacterJavaType<WrapCharacterRecord> implements AutoRegisteredJavaType<WrapCharacterRecord> {
     public WrapCharacterRecordJavaType() {
         super(WrapCharacterRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapDoubleClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapDoubleClassJavaType.java
index 3effe47..451c16c 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapDoubleClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapDoubleClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedDoubleJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapDoubleClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapDoubleClassJavaType extends WrappedDoubleJavaType<WrapDoubleClass> implements AutoRegisteredJavaType<WrapDoubleClass> {
     public WrapDoubleClassJavaType() {
         super(WrapDoubleClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapDoubleRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapDoubleRecordJavaType.java
index bf5b975..008b9b2 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapDoubleRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapDoubleRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedDoubleJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapDoubleRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapDoubleRecordJavaType extends WrappedDoubleJavaType<WrapDoubleRecord> implements AutoRegisteredJavaType<WrapDoubleRecord> {
     public WrapDoubleRecordJavaType() {
         super(WrapDoubleRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapEnumClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapEnumClassJavaType.java
index ffb45e5..39b4a62 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapEnumClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapEnumClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedEnumJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapEnumClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapEnumClassJavaType extends WrappedEnumJavaType<WrapEnumClass> implements AutoRegisteredJavaType<WrapEnumClass> {
     public WrapEnumClassJavaType() {
         super(WrapEnumClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapEnumRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapEnumRecordJavaType.java
index 759abfa..ae16ef6 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapEnumRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapEnumRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedEnumJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapEnumRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapEnumRecordJavaType extends WrappedEnumJavaType<WrapEnumRecord> implements AutoRegisteredJavaType<WrapEnumRecord> {
     public WrapEnumRecordJavaType() {
         super(WrapEnumRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapFloatClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapFloatClassJavaType.java
index 6d6ea8f..bf50a69 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapFloatClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapFloatClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedFloatJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapFloatClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapFloatClassJavaType extends WrappedFloatJavaType<WrapFloatClass> implements AutoRegisteredJavaType<WrapFloatClass> {
     public WrapFloatClassJavaType() {
         super(WrapFloatClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapFloatRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapFloatRecordJavaType.java
index 7784534..a15b6c1 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapFloatRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapFloatRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedFloatJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapFloatRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapFloatRecordJavaType extends WrappedFloatJavaType<WrapFloatRecord> implements AutoRegisteredJavaType<WrapFloatRecord> {
     public WrapFloatRecordJavaType() {
         super(WrapFloatRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapIntegerClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapIntegerClassJavaType.java
index 18d9448..cc846df 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapIntegerClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapIntegerClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedIntegerJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapIntegerClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapIntegerClassJavaType extends WrappedIntegerJavaType<WrapIntegerClass> implements AutoRegisteredJavaType<WrapIntegerClass> {
     public WrapIntegerClassJavaType() {
         super(WrapIntegerClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapIntegerRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapIntegerRecordJavaType.java
index 4f20a8a..ba8bc39 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapIntegerRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapIntegerRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedIntegerJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapIntegerRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapIntegerRecordJavaType extends WrappedIntegerJavaType<WrapIntegerRecord> implements AutoRegisteredJavaType<WrapIntegerRecord> {
     public WrapIntegerRecordJavaType() {
         super(WrapIntegerRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapLongClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapLongClassJavaType.java
index 9e3d566..ea2b49a 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapLongClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapLongClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedLongJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapLongClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapLongClassJavaType extends WrappedLongJavaType<WrapLongClass> implements AutoRegisteredJavaType<WrapLongClass> {
     public WrapLongClassJavaType() {
         super(WrapLongClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapLongRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapLongRecordJavaType.java
index c9aa18b..29e79f2 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapLongRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapLongRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedLongJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapLongRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapLongRecordJavaType extends WrappedLongJavaType<WrapLongRecord> implements AutoRegisteredJavaType<WrapLongRecord> {
     public WrapLongRecordJavaType() {
         super(WrapLongRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapScaledBigDecimalClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapScaledBigDecimalClassJavaType.java
index a667252..e42ac90 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapScaledBigDecimalClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapScaledBigDecimalClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedScaledBigDecimalJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapScaledBigDecimalClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapScaledBigDecimalClassJavaType extends WrappedScaledBigDecimalJavaType<WrapScaledBigDecimalClass> implements AutoRegisteredJavaType<WrapScaledBigDecimalClass> {
     public WrapScaledBigDecimalClassJavaType() {
         super(WrapScaledBigDecimalClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapScaledBigDecimalRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapScaledBigDecimalRecordJavaType.java
index dea2da4..9194302 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapScaledBigDecimalRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapScaledBigDecimalRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedScaledBigDecimalJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapScaledBigDecimalRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapScaledBigDecimalRecordJavaType extends WrappedScaledBigDecimalJavaType<WrapScaledBigDecimalRecord> implements AutoRegisteredJavaType<WrapScaledBigDecimalRecord> {
     public WrapScaledBigDecimalRecordJavaType() {
         super(WrapScaledBigDecimalRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapShortClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapShortClassJavaType.java
index f1d62d2..0bcd673 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapShortClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapShortClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedShortJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapShortClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapShortClassJavaType extends WrappedShortJavaType<WrapShortClass> implements AutoRegisteredJavaType<WrapShortClass> {
     public WrapShortClassJavaType() {
         super(WrapShortClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapShortRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapShortRecordJavaType.java
index 77885ba..1c3f217 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapShortRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapShortRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedShortJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapShortRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapShortRecordJavaType extends WrappedShortJavaType<WrapShortRecord> implements AutoRegisteredJavaType<WrapShortRecord> {
     public WrapShortRecordJavaType() {
         super(WrapShortRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapStringClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapStringClassJavaType.java
index def61a4..bf86a74 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapStringClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapStringClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedStringJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapStringClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapStringClassJavaType extends WrappedStringJavaType<WrapStringClass> implements AutoRegisteredJavaType<WrapStringClass> {
     public WrapStringClassJavaType() {
         super(WrapStringClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapStringRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapStringRecordJavaType.java
index 5e9bc43..f67bf4f 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapStringRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapStringRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedStringJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapStringRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapStringRecordJavaType extends WrappedStringJavaType<WrapStringRecord> implements AutoRegisteredJavaType<WrapStringRecord> {
     public WrapStringRecordJavaType() {
         super(WrapStringRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapUUIDClassJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapUUIDClassJavaType.java
index e5f0e75..9eafda9 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapUUIDClassJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapUUIDClassJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedUUIDJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapUUIDClass;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapUUIDClassJavaType extends WrappedUUIDJavaType<WrapUUIDClass> implements AutoRegisteredJavaType<WrapUUIDClass> {
     public WrapUUIDClassJavaType() {
         super(WrapUUIDClass.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapUUIDRecordJavaType.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapUUIDRecordJavaType.java
index 23ed29a..49a1e1c 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapUUIDRecordJavaType.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/javatype/WrapUUIDRecordJavaType.java
@@ -3,7 +3,9 @@
 import it.aboutbits.springboot.toolbox.autoconfiguration.persistence.AutoRegisteredJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.base.WrappedUUIDJavaType;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapUUIDRecord;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public final class WrapUUIDRecordJavaType extends WrappedUUIDJavaType<WrapUUIDRecord> implements AutoRegisteredJavaType<WrapUUIDRecord> {
     public WrapUUIDRecordJavaType() {
         super(WrapUUIDRecord.class);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/jpa/WrapperTypesModel.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/jpa/WrapperTypesModel.java
index 971c28c..fcad430 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/jpa/WrapperTypesModel.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/jpa/WrapperTypesModel.java
@@ -71,12 +71,16 @@
 import org.hibernate.annotations.JdbcType;
 import org.hibernate.type.descriptor.jdbc.CharJdbcType;
 import org.hibernate.type.descriptor.jdbc.UUIDJdbcType;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.NullUnmarked;
 
 @Entity
 @Getter
 @Setter
 @Table(name = "wrapper_type_test_model")
-public class WrapperTypesModel implements Identified<WrapperTypesModel.ID> {
+@NullUnmarked
+public class WrapperTypesModel implements Identified<WrapperTypesModel.@NonNull ID> {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     @JavaType(ID.JavaType.class)
@@ -206,6 +210,7 @@ public class WrapperTypesModel implements Identified<WrapperTypesModel.ID> {
     @JavaType(WrapEnumClassJavaType.class)
     private WrapEnumClass enumValueClass;
 
+    @NullMarked
     public record ID(
             Long value
     ) implements EntityId<Long> {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/jpa/WrapperTypesModelRepository.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/jpa/WrapperTypesModelRepository.java
index ca4c724..9250b40 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/jpa/WrapperTypesModelRepository.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/jpa/WrapperTypesModelRepository.java
@@ -28,68 +28,71 @@
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapStringRecord;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapUUIDClass;
 import it.aboutbits.springboot.toolbox.persistence.javatype.impl.type.WrapUUIDRecord;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import java.util.Optional;
 
+@NullMarked
 public interface WrapperTypesModelRepository extends JpaRepository<WrapperTypesModel, WrapperTypesModel.ID> {
-    Optional<WrapperTypesModel> findByBigDecimalValue(WrapBigDecimalRecord value);
+    Optional<WrapperTypesModel> findByBigDecimalValue(@Nullable WrapBigDecimalRecord value);
 
-    Optional<WrapperTypesModel> findByBigIntegerValue(WrapBigIntegerRecord value);
+    Optional<WrapperTypesModel> findByBigIntegerValue(@Nullable WrapBigIntegerRecord value);
 
-    Optional<WrapperTypesModel> findByDoubleValue(WrapDoubleRecord value);
+    Optional<WrapperTypesModel> findByDoubleValue(@Nullable WrapDoubleRecord value);
 
-    Optional<WrapperTypesModel> findByFloatValue(WrapFloatRecord value);
+    Optional<WrapperTypesModel> findByFloatValue(@Nullable WrapFloatRecord value);
 
-    Optional<WrapperTypesModel> findByIntegerValue(WrapIntegerRecord value);
+    Optional<WrapperTypesModel> findByIntegerValue(@Nullable WrapIntegerRecord value);
 
-    Optional<WrapperTypesModel> findByLongValue(WrapLongRecord value);
+    Optional<WrapperTypesModel> findByLongValue(@Nullable WrapLongRecord value);
 
-    Optional<WrapperTypesModel> findByScaledBigDecimalValue(WrapScaledBigDecimalRecord value);
+    Optional<WrapperTypesModel> findByScaledBigDecimalValue(@Nullable WrapScaledBigDecimalRecord value);
 
-    Optional<WrapperTypesModel> findByShortValue(WrapShortRecord value);
+    Optional<WrapperTypesModel> findByShortValue(@Nullable WrapShortRecord value);
 
-    Optional<WrapperTypesModel> findByStringValue(WrapStringRecord value);
+    Optional<WrapperTypesModel> findByStringValue(@Nullable WrapStringRecord value);
 
-    Optional<WrapperTypesModel> findByBoolValue(WrapBooleanRecord value);
+    Optional<WrapperTypesModel> findByBoolValue(@Nullable WrapBooleanRecord value);
 
-    Optional<WrapperTypesModel> findByByteValue(WrapByteRecord value);
+    Optional<WrapperTypesModel> findByByteValue(@Nullable WrapByteRecord value);
 
-    Optional<WrapperTypesModel> findByCharValue(WrapCharacterRecord value);
+    Optional<WrapperTypesModel> findByCharValue(@Nullable WrapCharacterRecord value);
 
-    Optional<WrapperTypesModel> findByUuidValue(WrapUUIDRecord value);
+    Optional<WrapperTypesModel> findByUuidValue(@Nullable WrapUUIDRecord value);
 
-    Optional<WrapperTypesModel> findByUuidValueAsString(WrapUUIDRecord value);
+    Optional<WrapperTypesModel> findByUuidValueAsString(@Nullable WrapUUIDRecord value);
 
-    Optional<WrapperTypesModel> findByBigDecimalValueClass(WrapBigDecimalClass value);
+    Optional<WrapperTypesModel> findByBigDecimalValueClass(@Nullable WrapBigDecimalClass value);
 
-    Optional<WrapperTypesModel> findByBigIntegerValueClass(WrapBigIntegerClass value);
+    Optional<WrapperTypesModel> findByBigIntegerValueClass(@Nullable WrapBigIntegerClass value);
 
-    Optional<WrapperTypesModel> findByDoubleValueClass(WrapDoubleClass value);
+    Optional<WrapperTypesModel> findByDoubleValueClass(@Nullable WrapDoubleClass value);
 
-    Optional<WrapperTypesModel> findByFloatValueClass(WrapFloatClass value);
+    Optional<WrapperTypesModel> findByFloatValueClass(@Nullable WrapFloatClass value);
 
-    Optional<WrapperTypesModel> findByIntegerValueClass(WrapIntegerClass value);
+    Optional<WrapperTypesModel> findByIntegerValueClass(@Nullable WrapIntegerClass value);
 
-    Optional<WrapperTypesModel> findByLongValueClass(WrapLongClass value);
+    Optional<WrapperTypesModel> findByLongValueClass(@Nullable WrapLongClass value);
 
-    Optional<WrapperTypesModel> findByScaledBigDecimalValueClass(WrapScaledBigDecimalClass value);
+    Optional<WrapperTypesModel> findByScaledBigDecimalValueClass(@Nullable WrapScaledBigDecimalClass value);
 
-    Optional<WrapperTypesModel> findByShortValueClass(WrapShortClass value);
+    Optional<WrapperTypesModel> findByShortValueClass(@Nullable WrapShortClass value);
 
-    Optional<WrapperTypesModel> findByStringValueClass(WrapStringClass value);
+    Optional<WrapperTypesModel> findByStringValueClass(@Nullable WrapStringClass value);
 
-    Optional<WrapperTypesModel> findByBoolValueClass(WrapBooleanClass value);
+    Optional<WrapperTypesModel> findByBoolValueClass(@Nullable WrapBooleanClass value);
 
-    Optional<WrapperTypesModel> findByByteValueClass(WrapByteClass value);
+    Optional<WrapperTypesModel> findByByteValueClass(@Nullable WrapByteClass value);
 
-    Optional<WrapperTypesModel> findByCharValueClass(WrapCharacterClass value);
+    Optional<WrapperTypesModel> findByCharValueClass(@Nullable WrapCharacterClass value);
 
-    Optional<WrapperTypesModel> findByUuidValueClass(WrapUUIDClass value);
+    Optional<WrapperTypesModel> findByUuidValueClass(@Nullable WrapUUIDClass value);
 
-    Optional<WrapperTypesModel> findByUuidValueClassAsString(WrapUUIDClass value);
+    Optional<WrapperTypesModel> findByUuidValueClassAsString(@Nullable WrapUUIDClass value);
 
-    Optional<WrapperTypesModel> findByEnumValue(WrapEnumRecord value);
+    Optional<WrapperTypesModel> findByEnumValue(@Nullable WrapEnumRecord value);
 
-    Optional<WrapperTypesModel> findByEnumValueClass(WrapEnumClass value);
+    Optional<WrapperTypesModel> findByEnumValueClass(@Nullable WrapEnumClass value);
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/SampleEnum.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/SampleEnum.java
index 5b6a8e6..d5ad625 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/SampleEnum.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/SampleEnum.java
@@ -1,5 +1,8 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
+import org.jspecify.annotations.NullMarked;
+
+@NullMarked
 public enum SampleEnum {
     A, B, C
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigDecimalClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigDecimalClass.java
index 177142b..fb00c66 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigDecimalClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigDecimalClass.java
@@ -5,6 +5,7 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 import java.math.BigDecimal;
 
@@ -12,6 +13,7 @@
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapBigDecimalClass implements CustomType<BigDecimal> {
     private final BigDecimal value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigDecimalRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigDecimalRecord.java
index 5291d1b..f894981 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigDecimalRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigDecimalRecord.java
@@ -1,9 +1,11 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
 import java.math.BigDecimal;
 
+@NullMarked
 public record WrapBigDecimalRecord(BigDecimal value) implements CustomType<BigDecimal> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigIntegerClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigIntegerClass.java
index 366a187..25c769c 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigIntegerClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigIntegerClass.java
@@ -5,6 +5,7 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 import java.math.BigInteger;
 
@@ -12,6 +13,7 @@
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapBigIntegerClass implements CustomType<BigInteger> {
     private final BigInteger value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigIntegerRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigIntegerRecord.java
index 7c86200..7cad17b 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigIntegerRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBigIntegerRecord.java
@@ -1,9 +1,11 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
 import java.math.BigInteger;
 
+@NullMarked
 public record WrapBigIntegerRecord(BigInteger value) implements CustomType<BigInteger> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBooleanClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBooleanClass.java
index 70325a9..a417b38 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBooleanClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBooleanClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapBooleanClass implements CustomType<Boolean> {
     private final Boolean value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBooleanRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBooleanRecord.java
index f0319ae..2851d04 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBooleanRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapBooleanRecord.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapBooleanRecord(Boolean value) implements CustomType<Boolean> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapByteClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapByteClass.java
index 6f15e3a..cd904e3 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapByteClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapByteClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapByteClass implements CustomType<Byte> {
     private final Byte value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapByteRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapByteRecord.java
index a30f64e..4608ca8 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapByteRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapByteRecord.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapByteRecord(Byte value) implements CustomType<Byte> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapCharacterClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapCharacterClass.java
index 46c0e6d..6a05505 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapCharacterClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapCharacterClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapCharacterClass implements CustomType<Character> {
     private final Character value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapCharacterRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapCharacterRecord.java
index 3a52373..8bf4cef 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapCharacterRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapCharacterRecord.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapCharacterRecord(Character value) implements CustomType<Character> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapDoubleClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapDoubleClass.java
index 2b56662..5246c55 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapDoubleClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapDoubleClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapDoubleClass implements CustomType<Double> {
     private final Double value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapDoubleRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapDoubleRecord.java
index e2825a8..c3bc51d 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapDoubleRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapDoubleRecord.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapDoubleRecord(Double value) implements CustomType<Double> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapEnumClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapEnumClass.java
index 242d4ba..47b6207 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapEnumClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapEnumClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapEnumClass implements CustomType<SampleEnum> {
     private final SampleEnum value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapEnumRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapEnumRecord.java
index 4c024fa..a4fe0d9 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapEnumRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapEnumRecord.java
@@ -1,6 +1,8 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapEnumRecord(SampleEnum value) implements CustomType<SampleEnum> {
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapFloatClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapFloatClass.java
index 9feb2b7..b270eb9 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapFloatClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapFloatClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapFloatClass implements CustomType<Float> {
     private final Float value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapFloatRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapFloatRecord.java
index 62b966d..dab5ac9 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapFloatRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapFloatRecord.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapFloatRecord(Float value) implements CustomType<Float> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapIntegerClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapIntegerClass.java
index 8c12927..23b4f00 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapIntegerClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapIntegerClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapIntegerClass implements CustomType<Integer> {
     private final Integer value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapIntegerRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapIntegerRecord.java
index 08ba7f1..c971953 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapIntegerRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapIntegerRecord.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapIntegerRecord(Integer value) implements CustomType<Integer> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapLongClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapLongClass.java
index 5ace546..c796f23 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapLongClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapLongClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapLongClass implements CustomType<Long> {
     private final Long value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapLongRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapLongRecord.java
index e77c55e..606cc1b 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapLongRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapLongRecord.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapLongRecord(Long value) implements CustomType<Long> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapScaledBigDecimalClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapScaledBigDecimalClass.java
index b078910..60d92f8 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapScaledBigDecimalClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapScaledBigDecimalClass.java
@@ -6,11 +6,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapScaledBigDecimalClass implements CustomType<ScaledBigDecimal> {
     private final ScaledBigDecimal value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapScaledBigDecimalRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapScaledBigDecimalRecord.java
index 966f2c6..73a70cd 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapScaledBigDecimalRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapScaledBigDecimalRecord.java
@@ -2,7 +2,9 @@
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapScaledBigDecimalRecord(ScaledBigDecimal value) implements CustomType<ScaledBigDecimal> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapShortClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapShortClass.java
index 7d2b8a5..479375b 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapShortClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapShortClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapShortClass implements CustomType<Short> {
     private final Short value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapShortRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapShortRecord.java
index 742e668..34bb921 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapShortRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapShortRecord.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapShortRecord(Short value) implements CustomType<Short> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapStringClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapStringClass.java
index b435c6c..277bd9e 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapStringClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapStringClass.java
@@ -5,11 +5,13 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 @Getter
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapStringClass implements CustomType<String> {
     private final String value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapStringRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapStringRecord.java
index 964f2b5..d0cf5a2 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapStringRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapStringRecord.java
@@ -1,7 +1,9 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
+@NullMarked
 public record WrapStringRecord(String value) implements CustomType<String> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapUUIDClass.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapUUIDClass.java
index 3087dae..2a98b9f 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapUUIDClass.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapUUIDClass.java
@@ -5,6 +5,7 @@
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.experimental.Accessors;
+import org.jspecify.annotations.NullMarked;
 
 import java.util.UUID;
 
@@ -12,6 +13,7 @@
 @Accessors(fluent = true)
 @EqualsAndHashCode
 @RequiredArgsConstructor
+@NullMarked
 public class WrapUUIDClass implements CustomType<UUID> {
     private final UUID value;
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapUUIDRecord.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapUUIDRecord.java
index 0c93286..f172490 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapUUIDRecord.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/javatype/impl/type/WrapUUIDRecord.java
@@ -1,9 +1,11 @@
 package it.aboutbits.springboot.toolbox.persistence.javatype.impl.type;
 
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
 
 import java.util.UUID;
 
+@NullMarked
 public record WrapUUIDRecord(UUID value) implements CustomType<UUID> {
 
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/QueryTransformerTest.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/QueryTransformerTest.java
index c0223ad..76cb3b6 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/QueryTransformerTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/QueryTransformerTest.java
@@ -6,6 +6,8 @@
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
 import jakarta.persistence.EntityManager;
 import jakarta.persistence.EntityNotFoundException;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -14,7 +16,8 @@
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 @ApplicationTest
-public class QueryTransformerTest {
+@NullMarked
+class QueryTransformerTest {
 
     @Autowired
     EntityManager entityManager;
@@ -73,7 +76,6 @@ void givenQueryWithPrimitiveCustomTypedResult_shouldPass() {
             assertThat(result.get()).isEqualByComparingTo(ScaledBigDecimal.valueOf(3.14));
         }
 
-
         @Test
         void givenQueryWithOneResult_shouldPass() {
             createTestModel("abc");
@@ -197,7 +199,6 @@ void givenQuery_singleUnboxedEntityResult_shouldPass() {
             assertThat(result.getFirst().getName()).isEqualTo(testModel.getName());
         }
 
-
         @Test
         void givenQuery_shouldPass() {
             var testModel = createTestModel("abc");
@@ -383,7 +384,11 @@ protected record WrongContainer(
     ) {
     }
 
-    private QueryTransformerTestModel createTestModel(String name, String email, ScaledBigDecimal scaledBigDecimal) {
+    private QueryTransformerTestModel createTestModel(
+            String name,
+            @Nullable String email,
+            ScaledBigDecimal scaledBigDecimal
+    ) {
         var item = new QueryTransformerTestModel();
         item.setName(name);
         item.setEmail(email);
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTransformerTest.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTransformerTest.java
index 7a7c54d..65662b7 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTransformerTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/TupleTransformerTest.java
@@ -1,9 +1,14 @@
 package it.aboutbits.springboot.toolbox.persistence.transformer;
 
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreGroupName;
 import it.aboutbits.springboot.toolbox.type.EmailAddress;
 import it.aboutbits.springboot.toolbox.type.Iban;
 import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
 import lombok.Data;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.NullUnmarked;
+import org.jspecify.annotations.Nullable;
+import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
@@ -12,205 +17,252 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-public class TupleTransformerTest {
-
-    @Test
-    void createObjectWithPrimitiveFields_givenPrimitives_shouldPass() {
-        // given
-        var tupleTransformer = new TupleTransformer<>(DataClassWithPrimitives.class);
-
-        // when
-        var result = tupleTransformer.transform(new Object[]{7L, 12, true});
-
-        // then
-        assertThat(result.longField).isEqualTo(7L);
-        assertThat(result.intField).isEqualTo(12);
-        assertThat(result.booleanField).isTrue();
-    }
-
-    @Test
-    void createObjectWithCustomTypedFields_shouldPass() {
-        // given
-        var tupleTransformer = new TupleTransformer<>(DataRecordWithCustomType.class);
-
-        // when
-        var result = tupleTransformer.transform(
-                new Object[]{
-                        3.14d,
-                        "IT27S0300203280975461985512",
-                        "info@aboutbits.it"
-                }
-        );
-
-        // then
-        assertThat(result.scaledBigDecimal).isEqualByComparingTo(ScaledBigDecimal.valueOf(3.14));
-        assertThat(result.emailAddress).isEqualTo(new EmailAddress("info@aboutbits.it"));
-        assertThat(result.iban).isEqualTo(new Iban("IT27S0300203280975461985512"));
+@NullMarked
+class TupleTransformerTest {
+    @Nested
+    @ArchIgnoreGroupName
+    class SimpleSimpleValue {
+        @Test
+        void actualValue_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(String.class);
+
+            // when
+            var result = tupleTransformer.transformTuple(new Object[]{"Sepp"}, new String[]{});
+
+            // then
+            assertThat(result).isEqualTo("Sepp");
+        }
+
+        @Test
+        void null_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(String.class);
+
+            // when
+            var result = tupleTransformer.transformTuple(new @Nullable Object[]{null}, new String[]{});
+
+            // then
+            assertThat(result).isNull();
+        }
     }
 
-    @Test
-    void createObjectWithPrimitiveFields_givenBoxedObjects_shouldPass() {
-        // given
-        var tupleTransformer = new TupleTransformer<>(DataClassWithPrimitives.class);
-        var l = Long.valueOf(7);
-        var i = Integer.valueOf(12);
-        var b = Boolean.valueOf(true);
-        var objectsUnderTest = new Object[]{l, i, b};
-
-        // when
-        var result = tupleTransformer.transform(objectsUnderTest);
-
-        // then
-        assertThat(result.longField).isEqualTo(7L);
-        assertThat(result.intField).isEqualTo(12);
-        assertThat(result.booleanField).isTrue();
+    @SuppressWarnings("NullAway")
+    @Nested
+    @ArchIgnoreGroupName
+    class WithPrimitives {
+        @Test
+        void createObjectWithPrimitiveFields_givenPrimitives_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(DataClassWithPrimitives.class);
+
+            // when
+            var result = tupleTransformer.transformTuple(new Object[]{7L, 12, true}, new String[]{});
+
+            // then
+            assertThat(result).isNotNull();
+            assertThat(result.longField).isEqualTo(7L);
+            assertThat(result.intField).isEqualTo(12);
+            assertThat(result.booleanField).isTrue();
+        }
+
+        @Test
+        void createObjectWithPrimitiveFields_givenBoxedObjects_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(DataClassWithPrimitives.class);
+            var l = Long.valueOf(7);
+            var i = Integer.valueOf(12);
+            var b = Boolean.valueOf(true);
+            var objectsUnderTest = new Object[]{l, i, b};
+
+            // when
+            var result = tupleTransformer.transformTuple(objectsUnderTest, new String[]{});
+
+            // then
+            assertThat(result).isNotNull();
+            assertThat(result.longField).isEqualTo(7L);
+            assertThat(result.intField).isEqualTo(12);
+            assertThat(result.booleanField).isTrue();
+        }
     }
 
-
-    @Test
-    void createRecord_givenMixedObjects_shouldPass() {
-        // given
-        var tupleTransformer = new TupleTransformer<>(DataRecord.class);
-        var l = Long.valueOf(7);
-        var b = Boolean.valueOf(true);
-        var objectsUnderTest = new Object[]{
-                l, b, "String123", false, SomeEnum.ENUM_1, UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88")
-        };
-
-        // when
-        var result = tupleTransformer.transform(objectsUnderTest);
-
-        // then
-        assertThat(result.longField).isEqualTo(7L);
-        assertThat(result.booleanBoxed).isTrue();
-        assertThat(result.string).isEqualTo("String123");
-        assertThat(result.booleanPrimitive).isFalse();
-        assertThat(result.anEnum).isEqualTo(SomeEnum.ENUM_1);
-        assertThat(result.uuid).isEqualTo(UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88"));
+    @SuppressWarnings("NullAway")
+    @Nested
+    @ArchIgnoreGroupName
+    class WithCustomTypes {
+        @Test
+        void createObjectWithCustomTypedFields_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(DataRecordWithCustomType.class);
+
+            // when
+            var result = tupleTransformer.transformTuple(
+                    new Object[]{
+                            3.14d,
+                            "IT27S0300203280975461985512",
+                            "info@aboutbits.it"
+                    },
+                    new String[]{}
+            );
+
+            // then
+            assertThat(result).isNotNull();
+            assertThat(result.scaledBigDecimal).isEqualByComparingTo(ScaledBigDecimal.valueOf(3.14));
+            assertThat(result.emailAddress).isEqualTo(new EmailAddress("info@aboutbits.it"));
+            assertThat(result.iban).isEqualTo(new Iban("IT27S0300203280975461985512"));
+        }
     }
 
-
-    @Test
-    void createRecord_givenMixedObjects_enumValueAsString_shouldPass() {
-        // given
-        var tupleTransformer = new TupleTransformer<>(DataRecord.class);
-        var l = Long.valueOf(7);
-        var b = Boolean.valueOf(true);
-        var objectsUnderTest = new Object[]{
-                l, b, "String123", false, "ENUM_1", UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88")
-        };
-
-        // when
-        var result = tupleTransformer.transform(objectsUnderTest);
-
-        // then
-        assertThat(result.longField).isEqualTo(7L);
-        assertThat(result.booleanBoxed).isTrue();
-        assertThat(result.string).isEqualTo("String123");
-        assertThat(result.booleanPrimitive).isFalse();
-        assertThat(result.anEnum).isEqualTo(SomeEnum.ENUM_1);
-        assertThat(result.uuid).isEqualTo(UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88"));
-    }
-
-
-    @Test
-    void createRecordInsideAClass_givenMixedObjects_shouldPass() {
-        // given
-        var tupleTransformer = new TupleTransformer<>(DataRecordParent.class);
-        var rec = new DataRecord(
-                7L,
-                true,
-                "String123",
-                false,
-                SomeEnum.ENUM_1,
-                UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88")
-        );
-        var objectsUnderTest = new Object[]{rec, 33};
-
-        // when
-        var result = tupleTransformer.transform(objectsUnderTest);
-
-        // then
-        assertThat(result.dataRecord.longField).isEqualTo(7L);
-        assertThat(result.dataRecord.booleanBoxed).isTrue();
-        assertThat(result.dataRecord.string).isEqualTo("String123");
-        assertThat(result.dataRecord.booleanPrimitive).isFalse();
-        assertThat(result.dataRecord.anEnum).isEqualTo(SomeEnum.ENUM_1);
-        assertThat(result.dataRecord.uuid).isEqualTo(UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88"));
-        assertThat(result.someOtherField).isEqualTo(33);
+    @SuppressWarnings("NullAway")
+    @Nested
+    @ArchIgnoreGroupName
+    class Records {
+        @Test
+        void createRecord_givenMixedObjects_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(DataRecord.class);
+            var l = Long.valueOf(7);
+            var b = Boolean.valueOf(true);
+            var objectsUnderTest = new Object[]{
+                    l, b, "String123", false, SomeEnum.ENUM_1, UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88")
+            };
+
+            // when
+            var result = tupleTransformer.transformTuple(objectsUnderTest, new String[]{});
+
+            // then
+            assertThat(result).isNotNull();
+            assertThat(result.longField).isEqualTo(7L);
+            assertThat(result.booleanBoxed).isTrue();
+            assertThat(result.string).isEqualTo("String123");
+            assertThat(result.booleanPrimitive).isFalse();
+            assertThat(result.anEnum).isEqualTo(SomeEnum.ENUM_1);
+            assertThat(result.uuid).isEqualTo(UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88"));
+        }
+
+        @Test
+        void createRecord_givenMixedObjects_enumValueAsString_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(DataRecord.class);
+            var l = Long.valueOf(7);
+            var b = Boolean.valueOf(true);
+            var objectsUnderTest = new Object[]{
+                    l, b, "String123", false, "ENUM_1", UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88")
+            };
+
+            // when
+            var result = tupleTransformer.transformTuple(objectsUnderTest, new String[]{});
+
+            // then
+            assertThat(result).isNotNull();
+            assertThat(result.longField).isEqualTo(7L);
+            assertThat(result.booleanBoxed).isTrue();
+            assertThat(result.string).isEqualTo("String123");
+            assertThat(result.booleanPrimitive).isFalse();
+            assertThat(result.anEnum).isEqualTo(SomeEnum.ENUM_1);
+            assertThat(result.uuid).isEqualTo(UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88"));
+        }
+
+        @Test
+        void createRecordInsideAClass_givenMixedObjects_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(DataRecordParent.class);
+            var rec = new DataRecord(
+                    7L,
+                    true,
+                    "String123",
+                    false,
+                    SomeEnum.ENUM_1,
+                    UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88")
+            );
+            var objectsUnderTest = new Object[]{rec, 33};
+
+            // when
+            var result = tupleTransformer.transformTuple(objectsUnderTest, new String[]{});
+
+            // then
+            assertThat(result).isNotNull();
+            assertThat(result.dataRecord.longField).isEqualTo(7L);
+            assertThat(result.dataRecord.booleanBoxed).isTrue();
+            assertThat(result.dataRecord.string).isEqualTo("String123");
+            assertThat(result.dataRecord.booleanPrimitive).isFalse();
+            assertThat(result.dataRecord.anEnum).isEqualTo(SomeEnum.ENUM_1);
+            assertThat(result.dataRecord.uuid).isEqualTo(UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88"));
+            assertThat(result.someOtherField).isEqualTo(33);
+        }
+
+        @Test
+        void createRecord_givenMixedObjects_someNullValues_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(DataRecord.class);
+            var objectsUnderTest = new @Nullable Object[]{
+                    null, null, "String123", false, null, UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88")
+            };
+
+            // when
+            var result = tupleTransformer.transformTuple(objectsUnderTest, new String[]{});
+
+            // then
+            assertThat(result).isNotNull();
+            assertThat(result.longField).isNull();
+            assertThat(result.booleanBoxed).isNull();
+            assertThat(result.string).isEqualTo("String123");
+            assertThat(result.booleanPrimitive).isFalse();
+            assertThat(result.anEnum).isNull();
+            assertThat(result.uuid).isEqualTo(UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88"));
+        }
+
+        @Test
+        void createRecordInsideAClass_givenMixedObjectsAsList_shouldPass() {
+            // given
+            var tupleTransformer = new TupleTransformer<>(DataRecordParentWithList.class);
+            var rec1 = new DataRecord(
+                    7L,
+                    true,
+                    "String111",
+                    false,
+                    SomeEnum.ENUM_1,
+                    UUID.fromString("c3221989-b494-4227-b7e1-2f84fdc048f7")
+            );
+            var rec2 = new DataRecord(
+                    0L,
+                    null,
+                    "String222",
+                    false,
+                    SomeEnum.ENUM_2,
+                    UUID.fromString("25f6e0c2-4628-43a1-a703-e80926496fd1")
+            );
+            var list = new ArrayList<>();
+            list.add(rec1);
+            list.add(rec2);
+            var objectsUnderTest = new Object[]{list, 33};
+
+            // when
+            var result = tupleTransformer.transformTuple(objectsUnderTest, new String[]{});
+
+            // then
+            assertThat(result).isNotNull();
+
+            var firstRecord = result.dataRecords.getFirst();
+            assertThat(firstRecord.longField).isEqualTo(7L);
+            assertThat(firstRecord.booleanBoxed).isTrue();
+            assertThat(firstRecord.string).isEqualTo("String111");
+            assertThat(firstRecord.booleanPrimitive).isFalse();
+            assertThat(firstRecord.anEnum).isEqualTo(SomeEnum.ENUM_1);
+            assertThat(firstRecord.uuid).isEqualTo(UUID.fromString("c3221989-b494-4227-b7e1-2f84fdc048f7"));
+
+            var secondRecord = result.dataRecords.get(1);
+            assertThat(secondRecord.longField).isZero();
+            assertThat(secondRecord.booleanBoxed).isNull();
+            assertThat(secondRecord.string).isEqualTo("String222");
+            assertThat(secondRecord.booleanPrimitive).isFalse();
+            assertThat(secondRecord.anEnum).isEqualTo(SomeEnum.ENUM_2);
+            assertThat(secondRecord.uuid).isEqualTo(UUID.fromString("25f6e0c2-4628-43a1-a703-e80926496fd1"));
+
+            assertThat(result.someOtherField).isEqualTo(33);
+        }
     }
 
-
-    @Test
-    void createRecord_givenMixedObjects_someNullValues_shouldPass() {
-        // given
-        var tupleTransformer = new TupleTransformer<>(DataRecord.class);
-        var objectsUnderTest = new Object[]{
-                null, null, "String123", false, null, UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88")
-        };
-
-        // when
-        var result = tupleTransformer.transform(objectsUnderTest);
-
-        // then
-        assertThat(result.longField).isNull();
-        assertThat(result.booleanBoxed).isNull();
-        assertThat(result.string).isEqualTo("String123");
-        assertThat(result.booleanPrimitive).isFalse();
-        assertThat(result.anEnum).isNull();
-        assertThat(result.uuid).isEqualTo(UUID.fromString("f255a993-0086-4b4d-a62f-3aa174501f88"));
-    }
-
-
-    @Test
-    void createRecordInsideAClass_givenMixedObjectsAsList_shouldPass() {
-        // given
-        var tupleTransformer = new TupleTransformer<>(DataRecordParentWithList.class);
-        var rec1 = new DataRecord(
-                7L,
-                true,
-                "String111",
-                false,
-                SomeEnum.ENUM_1,
-                UUID.fromString("c3221989-b494-4227-b7e1-2f84fdc048f7")
-        );
-        var rec2 = new DataRecord(
-                0L,
-                null,
-                "String222",
-                false,
-                SomeEnum.ENUM_2,
-                UUID.fromString("25f6e0c2-4628-43a1-a703-e80926496fd1")
-        );
-        var list = new ArrayList<>();
-        list.add(rec1);
-        list.add(rec2);
-        var objectsUnderTest = new Object[]{list, 33};
-
-        // when
-        var result = tupleTransformer.transform(objectsUnderTest);
-
-        // then
-        var firstRecord = result.dataRecords.getFirst();
-        assertThat(firstRecord.longField).isEqualTo(7L);
-        assertThat(firstRecord.booleanBoxed).isTrue();
-        assertThat(firstRecord.string).isEqualTo("String111");
-        assertThat(firstRecord.booleanPrimitive).isFalse();
-        assertThat(firstRecord.anEnum).isEqualTo(SomeEnum.ENUM_1);
-        assertThat(firstRecord.uuid).isEqualTo(UUID.fromString("c3221989-b494-4227-b7e1-2f84fdc048f7"));
-
-        var secondRecord = result.dataRecords.get(1);
-        assertThat(secondRecord.longField).isZero();
-        assertThat(secondRecord.booleanBoxed).isNull();
-        assertThat(secondRecord.string).isEqualTo("String222");
-        assertThat(secondRecord.booleanPrimitive).isFalse();
-        assertThat(secondRecord.anEnum).isEqualTo(SomeEnum.ENUM_2);
-        assertThat(secondRecord.uuid).isEqualTo(UUID.fromString("25f6e0c2-4628-43a1-a703-e80926496fd1"));
-
-        assertThat(result.someOtherField).isEqualTo(33);
-    }
-
-
     @Data
     private static final class DataClassWithPrimitives {
         private final long longField;
@@ -218,6 +270,7 @@ private static final class DataClassWithPrimitives {
         private final boolean booleanField;
     }
 
+    @NullUnmarked
     protected record DataRecord(
             Long longField,
             Boolean booleanBoxed,
@@ -228,14 +281,12 @@ protected record DataRecord(
     ) {
     }
 
-
     protected record DataRecordParent(
             DataRecord dataRecord,
             long someOtherField
     ) {
     }
 
-
     protected record DataRecordWithCustomType(
             ScaledBigDecimal scaledBigDecimal,
             Iban iban,
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/impl/jpa/QueryTransformerTestModel.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/impl/jpa/QueryTransformerTestModel.java
index a2b4e8a..bf73011 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/impl/jpa/QueryTransformerTestModel.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/impl/jpa/QueryTransformerTestModel.java
@@ -17,6 +17,9 @@
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 import org.hibernate.annotations.JavaType;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.NullUnmarked;
 
 @Entity
 @Getter
@@ -25,7 +28,8 @@
 @Table(name = "query_transformer_test_model")
 @NoArgsConstructor
 @AllArgsConstructor
-public class QueryTransformerTestModel implements Identified<QueryTransformerTestModel.ID> {
+@NullUnmarked
+public class QueryTransformerTestModel implements Identified<QueryTransformerTestModel.@NonNull ID> {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     @JavaType(ID.JavaType.class)
@@ -39,6 +43,7 @@ public class QueryTransformerTestModel implements Identified<QueryTransformerTes
     @JavaType(ScaledBigDecimalJavaType.class)
     private ScaledBigDecimal scaledBigDecimalValue;
 
+    @NullMarked
     public record ID(
             Long value
     ) implements EntityId<Long> {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/impl/jpa/QueryTransformerTestModelRepository.java b/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/impl/jpa/QueryTransformerTestModelRepository.java
index cbeb0eb..3bb11c6 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/impl/jpa/QueryTransformerTestModelRepository.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/persistence/transformer/impl/jpa/QueryTransformerTestModelRepository.java
@@ -1,6 +1,8 @@
 package it.aboutbits.springboot.toolbox.persistence.transformer.impl.jpa;
 
+import org.jspecify.annotations.NullMarked;
 import org.springframework.data.jpa.repository.JpaRepository;
 
+@NullMarked
 public interface QueryTransformerTestModelRepository extends JpaRepository<QueryTransformerTestModel, QueryTransformerTestModel.ID> {
 }
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/reflection/util/CustomTypeReflectionUtilTest.java b/src/test/java/it/aboutbits/springboot/toolbox/reflection/util/CustomTypeReflectionUtilTest.java
index 48c9f7c..b91901e 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/reflection/util/CustomTypeReflectionUtilTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/reflection/util/CustomTypeReflectionUtilTest.java
@@ -2,11 +2,14 @@
 
 import it.aboutbits.springboot.toolbox.autoconfiguration.web.CustomTypeScanner;
 import it.aboutbits.springboot.toolbox.type.CustomType;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
+@NullMarked
 class CustomTypeReflectionUtilTest {
     @Test
     void testGetCustomTypeConstructorWithValidCustomType() throws Exception {
@@ -79,8 +82,9 @@ public String value() {
 
     @CustomTypeScanner.DisableCustomTypeConfiguration
     public static class InvalidCustomType implements CustomType<String> {
+        @SuppressWarnings("NullAway")
         @Override
-        public String value() {
+        public @Nullable String value() {
             return null;
         }
 
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/type/EmailAddressTest.java b/src/test/java/it/aboutbits/springboot/toolbox/type/EmailAddressTest.java
index 1efb6fa..8fc4720 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/type/EmailAddressTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/type/EmailAddressTest.java
@@ -1,5 +1,7 @@
 package it.aboutbits.springboot.toolbox.type;
 
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreGroupName;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -9,7 +11,9 @@
 import static org.assertj.core.api.Assertions.assertThatCode;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
 
+@NullMarked
 class EmailAddressTest {
+    @ArchIgnoreGroupName
     @Nested
     class Constructor {
         @ParameterizedTest
@@ -44,12 +48,14 @@ void invalidValues_shouldFail(String value) {
 
         @Test
         void null_shouldFail() {
+            //noinspection DataFlowIssue
             assertThatIllegalArgumentException().isThrownBy(
                     () -> new EmailAddress(null)
             );
         }
     }
 
+    @ArchIgnoreGroupName
     @Nested
     class ToStringAndValue {
         @Test
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/type/IbanTest.java b/src/test/java/it/aboutbits/springboot/toolbox/type/IbanTest.java
index 8311a93..6a3ae55 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/type/IbanTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/type/IbanTest.java
@@ -1,5 +1,7 @@
 package it.aboutbits.springboot.toolbox.type;
 
+import it.aboutbits.archunit.toolbox.support.ArchIgnoreGroupName;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -9,7 +11,9 @@
 import static org.assertj.core.api.Assertions.assertThatCode;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
 
+@NullMarked
 class IbanTest {
+    @ArchIgnoreGroupName
     @Nested
     class Constructor {
         @ParameterizedTest
@@ -49,12 +53,14 @@ void invalidValues_shouldFail(String value) {
 
         @Test
         void null_shouldFail() {
+            //noinspection DataFlowIssue
             assertThatIllegalArgumentException().isThrownBy(
                     () -> new Iban(null)
             );
         }
     }
 
+    @ArchIgnoreGroupName
     @Nested
     class ToStringAndValue {
         @Test
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/util/CollectUtilTest.java b/src/test/java/it/aboutbits/springboot/toolbox/util/CollectUtilTest.java
index dfb3a17..4d605fd 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/util/CollectUtilTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/util/CollectUtilTest.java
@@ -1,11 +1,14 @@
 package it.aboutbits.springboot.toolbox.util;
 
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.springframework.data.util.Streamable;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.function.Function;
 import java.util.stream.Stream;
@@ -15,6 +18,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+@NullMarked
 class CollectUtilTest {
     @Nested
     class CollectToSet {
@@ -23,7 +27,7 @@ class CollectToSet {
         void shouldConvertCollectionToSetUsingMapper() {
             // given
             var numbers = Arrays.asList(1, 2, 3, 4, 5);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(numbers, mapper);
@@ -37,7 +41,7 @@ void shouldConvertCollectionToSetUsingMapper() {
         void shouldConvertCollectionToSetUsingMapperAndFilterNullValues() {
             // given
             var numbers = Arrays.asList("a", "b", "c", "d");
-            var mapper = (Function<String, String>) Object::toString;
+            var mapper = (NullableFunction<String, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(numbers, mapper);
@@ -51,7 +55,7 @@ void shouldConvertCollectionToSetUsingMapperAndFilterNullValues() {
         void shouldHandleEmptyCollectionWhenConvertingToSet() {
             // given
             var emptyList = Collections.<Integer>emptyList();
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(emptyList, mapper);
@@ -65,7 +69,7 @@ void shouldHandleEmptyCollectionWhenConvertingToSet() {
         void shouldRemoveDuplicatesWhenConvertingCollectionToSet() {
             // given
             var numbersWithDuplicates = Arrays.asList(1, 2, 2, 3, 3, 3);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(numbersWithDuplicates, mapper);
@@ -80,7 +84,7 @@ void shouldRemoveDuplicatesWhenConvertingCollectionToSet() {
         void shouldConvertStreamableToSetUsingMapper() {
             // given
             var numbers = Streamable.of(1, 2, 3, 4, 5);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(numbers, mapper);
@@ -94,7 +98,7 @@ void shouldConvertStreamableToSetUsingMapper() {
         void shouldConvertStreamableToSetUsingMapperAndFilterNullValues() {
             // given
             var numbers = Streamable.of("a", "b", "c", "d");
-            var mapper = (Function<String, String>) Object::toString;
+            var mapper = (NullableFunction<String, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(numbers, mapper);
@@ -108,7 +112,7 @@ void shouldConvertStreamableToSetUsingMapperAndFilterNullValues() {
         void shouldHandleEmptyStreamableWhenConvertingToSet() {
             // given
             var emptyStreamable = Streamable.<Integer>empty();
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(emptyStreamable, mapper);
@@ -122,7 +126,7 @@ void shouldHandleEmptyStreamableWhenConvertingToSet() {
         void shouldConvertStreamToSetUsingMapper() {
             // given
             var numbers = java.util.stream.Stream.of(1, 2, 3, 4, 5);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(numbers, mapper);
@@ -136,7 +140,7 @@ void shouldConvertStreamToSetUsingMapper() {
         void shouldHandleEmptyStreamWhenConvertingToSet() {
             // given
             var emptyStream = java.util.stream.Stream.<Integer>empty();
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(emptyStream, mapper);
@@ -150,7 +154,7 @@ void shouldHandleEmptyStreamWhenConvertingToSet() {
         void shouldRemoveDuplicatesWhenConvertingStreamToSet() {
             // given
             var numbersWithDuplicates = java.util.stream.Stream.of(1, 2, 2, 3, 3, 3);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToSet(numbersWithDuplicates, mapper);
@@ -168,7 +172,7 @@ class CollectToList {
         void shouldConvertCollectionToListUsingMapper() {
             // given
             var numbers = Arrays.asList(1, 2, 3, 4, 5);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToList(numbers, mapper);
@@ -182,7 +186,7 @@ void shouldConvertCollectionToListUsingMapper() {
         void shouldHandleEmptyCollectionWhenConvertingToList() {
             // given
             var emptyList = Collections.<Integer>emptyList();
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToList(emptyList, mapper);
@@ -196,7 +200,7 @@ void shouldHandleEmptyCollectionWhenConvertingToList() {
         void shouldPreserveDuplicatesWhenConvertingCollectionToList() {
             // given
             var numbersWithDuplicates = Arrays.asList(1, 2, 2, 3, 3, 3);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToList(numbersWithDuplicates, mapper);
@@ -211,7 +215,7 @@ void shouldPreserveDuplicatesWhenConvertingCollectionToList() {
         void shouldConvertStreamableToListUsingMapper() {
             // given
             var numbers = Streamable.of(1, 2, 3, 4, 5);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToList(numbers, mapper);
@@ -225,7 +229,7 @@ void shouldConvertStreamableToListUsingMapper() {
         void shouldHandleEmptyStreamableWhenConvertingToList() {
             // given
             var emptyStreamable = Streamable.<Integer>empty();
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToList(emptyStreamable, mapper);
@@ -239,7 +243,7 @@ void shouldHandleEmptyStreamableWhenConvertingToList() {
         void shouldConvertStreamToListUsingMapper() {
             // given
             var numbers = java.util.stream.Stream.of(1, 2, 3, 4, 5);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToList(numbers, mapper);
@@ -253,7 +257,7 @@ void shouldConvertStreamToListUsingMapper() {
         void shouldHandleEmptyStreamWhenConvertingToList() {
             // given
             var emptyStream = java.util.stream.Stream.<Integer>empty();
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToList(emptyStream, mapper);
@@ -267,7 +271,7 @@ void shouldHandleEmptyStreamWhenConvertingToList() {
         void shouldPreserveDuplicatesWhenConvertingStreamToList() {
             // given
             var numbersWithDuplicates = java.util.stream.Stream.of(1, 2, 2, 3, 3, 3);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var result = CollectUtil.collectToList(numbersWithDuplicates, mapper);
@@ -285,7 +289,7 @@ class CollectToStream {
         void shouldConvertCollectionToStreamUsingMapper() {
             // given
             var numbers = Arrays.asList(1, 2, 3, 4, 5);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var resultStream = CollectUtil.collectToStream(numbers, mapper);
@@ -300,7 +304,7 @@ void shouldConvertCollectionToStreamUsingMapper() {
         void shouldHandleEmptyCollectionWhenConvertingToStream() {
             // given
             var emptyList = Collections.<Integer>emptyList();
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var resultStream = CollectUtil.collectToStream(emptyList, mapper);
@@ -315,7 +319,7 @@ void shouldHandleEmptyCollectionWhenConvertingToStream() {
         void shouldConvertStreamableToStreamUsingMapper() {
             // given
             var numbers = Streamable.of(1, 2, 3, 4, 5);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var resultStream = CollectUtil.collectToStream(numbers, mapper);
@@ -330,7 +334,7 @@ void shouldConvertStreamableToStreamUsingMapper() {
         void shouldHandleEmptyStreamableWhenConvertingToStream() {
             // given
             var emptyStreamable = Streamable.<Integer>empty();
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var resultStream = CollectUtil.collectToStream(emptyStreamable, mapper);
@@ -345,7 +349,7 @@ void shouldHandleEmptyStreamableWhenConvertingToStream() {
         void shouldConvertStreamToStreamUsingMapper() {
             // given
             var numbers = java.util.stream.Stream.of(1, 2, 3, 4, 5);
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var resultStream = CollectUtil.collectToStream(numbers, mapper);
@@ -360,7 +364,7 @@ void shouldConvertStreamToStreamUsingMapper() {
         void shouldHandleEmptyStreamWhenConvertingToStream() {
             // given
             var emptyStream = java.util.stream.Stream.<Integer>empty();
-            var mapper = (Function<Integer, String>) Object::toString;
+            var mapper = (NullableFunction<Integer, String>) Object::toString;
 
             // when
             var resultStream = CollectUtil.collectToStream(emptyStream, mapper);
@@ -377,7 +381,7 @@ class CollectToMap {
         @DisplayName("Should convert Collection to Map using key and value mappers")
         void shouldConvertCollectionToMapUsingMappers() {
             // given
-            var items = Arrays.asList("a", "bb", "ccc");
+            var items = (Collection<@Nullable String>) Arrays.asList("a", "bb", "ccc");
 
             // when
             var result = CollectUtil.collectToMap(items, String::length, Function.identity());
@@ -394,7 +398,7 @@ void shouldConvertCollectionToMapUsingMappers() {
         @DisplayName("Should throw on duplicate keys according to Collectors.toMap default behavior")
         void shouldThrowOnDuplicateKeys() {
             // given
-            var items = Arrays.asList("a", "b"); // both have length of 1
+            var items = (Collection<@Nullable String>) Arrays.asList("a", "b"); // both have length of 1
 
             // when / then
             assertThatIllegalStateException().isThrownBy(
@@ -427,7 +431,7 @@ void shouldConvertStreamableToMapUsingMappers() {
         @DisplayName("Should convert Stream to Map using key and value mappers")
         void shouldConvertStreamToMapUsingMappers() {
             // given
-            var items = Stream.of("m", "nn");
+            var items = Stream.<@Nullable String>of("m", "nn");
 
             // when
             var result = CollectUtil.collectToMap(items, String::length, Function.identity());
@@ -443,7 +447,7 @@ void shouldConvertStreamToMapUsingMappers() {
         @DisplayName("Should return empty map for empty collection")
         void shouldReturnEmptyMapForEmptyCollection() {
             // given
-            var items = Collections.<String>emptyList();
+            var items = Collections.<@Nullable String>emptyList();
 
             // when
             var result = CollectUtil.collectToMap(items, String::length, Function.identity());
@@ -469,7 +473,7 @@ void shouldReturnEmptyMapForEmptyStreamable() {
         @DisplayName("Should return empty map for empty stream")
         void shouldReturnEmptyMapForEmptyStream() {
             // given
-            var items = Stream.<String>empty();
+            var items = Stream.<@Nullable String>empty();
 
             // when
             var result = CollectUtil.collectToMap(items, String::length, Function.identity());
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/util/FilterUtilTest.java b/src/test/java/it/aboutbits/springboot/toolbox/util/FilterUtilTest.java
index 505955e..4272b64 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/util/FilterUtilTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/util/FilterUtilTest.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox.util;
 
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
@@ -12,6 +13,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+@NullMarked
 class FilterUtilTest {
     @Nested
     class FilterToSet {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/validation/util/EmailAddressValidatorTest.java b/src/test/java/it/aboutbits/springboot/toolbox/validation/util/EmailAddressValidatorTest.java
index 1ee4cc9..66afcf0 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/validation/util/EmailAddressValidatorTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/validation/util/EmailAddressValidatorTest.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox.validation.util;
 
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -7,6 +8,7 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@NullMarked
 class EmailAddressValidatorTest {
     @Nested
     class IsValid {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/validation/util/IbanValidatorTest.java b/src/test/java/it/aboutbits/springboot/toolbox/validation/util/IbanValidatorTest.java
index 7fbe7b1..ee923bf 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/validation/util/IbanValidatorTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/validation/util/IbanValidatorTest.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox.validation.util;
 
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -7,6 +8,7 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@NullMarked
 class IbanValidatorTest {
     @Nested
     class IsValid {
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/MaxScaledBigDecimalValidatorTest.java b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/MaxScaledBigDecimalValidatorTest.java
new file mode 100644
index 0000000..ab9a607
--- /dev/null
+++ b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/MaxScaledBigDecimalValidatorTest.java
@@ -0,0 +1,43 @@
+package it.aboutbits.springboot.toolbox.validation.validator;
+
+import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import jakarta.validation.Validation;
+import jakarta.validation.ValidatorFactory;
+import jakarta.validation.constraints.Max;
+import org.jspecify.annotations.NullMarked;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@NullMarked
+class MaxScaledBigDecimalValidatorTest {
+    private static final ValidatorFactory VALIDATOR_FACTORY = Validation.buildDefaultValidatorFactory();
+
+    record Sut(@Max(-50) ScaledBigDecimal value) {
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {-100_000_000.99999, -50.000001, -50})
+    void valid_shouldSucceed(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isEmpty();
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {-49.999999, -49, 0, 100_000_000})
+    void inValid_shouldFail(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isNotEmpty();
+    }
+}
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/MinScaledBigDecimalValidatorTest.java b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/MinScaledBigDecimalValidatorTest.java
new file mode 100644
index 0000000..a9aef51
--- /dev/null
+++ b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/MinScaledBigDecimalValidatorTest.java
@@ -0,0 +1,43 @@
+package it.aboutbits.springboot.toolbox.validation.validator;
+
+import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import jakarta.validation.Validation;
+import jakarta.validation.ValidatorFactory;
+import jakarta.validation.constraints.Min;
+import org.jspecify.annotations.NullMarked;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@NullMarked
+class MinScaledBigDecimalValidatorTest {
+    private static final ValidatorFactory VALIDATOR_FACTORY = Validation.buildDefaultValidatorFactory();
+
+    record Sut(@Min(50) ScaledBigDecimal value) {
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {50, 50.0000001, 100_000_000.9999})
+    void valid_shouldSucceed(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isEmpty();
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {-1, -0.0000001, 0, 49, 49.999999})
+    void inValid_shouldFail(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isNotEmpty();
+    }
+}
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeOrZeroScaledBigDecimalValidatorTest.java b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeOrZeroScaledBigDecimalValidatorTest.java
new file mode 100644
index 0000000..1c567eb
--- /dev/null
+++ b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeOrZeroScaledBigDecimalValidatorTest.java
@@ -0,0 +1,43 @@
+package it.aboutbits.springboot.toolbox.validation.validator;
+
+import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import jakarta.validation.Validation;
+import jakarta.validation.ValidatorFactory;
+import jakarta.validation.constraints.NegativeOrZero;
+import org.jspecify.annotations.NullMarked;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@NullMarked
+class NegativeOrZeroScaledBigDecimalValidatorTest {
+    private static final ValidatorFactory VALIDATOR_FACTORY = Validation.buildDefaultValidatorFactory();
+
+    record Sut(@NegativeOrZero ScaledBigDecimal value) {
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {-1, -0.0000001, 0})
+    void valid_shouldSucceed(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isEmpty();
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {0.0000001, 1, 100_000_000.9999})
+    void inValid_shouldFail(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isNotEmpty();
+    }
+}
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeScaledBigDecimalValidatorTest.java b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeScaledBigDecimalValidatorTest.java
new file mode 100644
index 0000000..6909a7f
--- /dev/null
+++ b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/NegativeScaledBigDecimalValidatorTest.java
@@ -0,0 +1,43 @@
+package it.aboutbits.springboot.toolbox.validation.validator;
+
+import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import jakarta.validation.Validation;
+import jakarta.validation.ValidatorFactory;
+import jakarta.validation.constraints.Negative;
+import org.jspecify.annotations.NullMarked;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@NullMarked
+class NegativeScaledBigDecimalValidatorTest {
+    private static final ValidatorFactory VALIDATOR_FACTORY = Validation.buildDefaultValidatorFactory();
+
+    record Sut(@Negative ScaledBigDecimal value) {
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {-1, -0.0000001})
+    void valid_shouldSucceed(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isEmpty();
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {0, 0.0000001, 1, 100_000_000.9999})
+    void inValid_shouldFail(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isNotEmpty();
+    }
+}
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveOrZeroScaledBigDecimalValidatorTest.java b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveOrZeroScaledBigDecimalValidatorTest.java
new file mode 100644
index 0000000..84f05e0
--- /dev/null
+++ b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveOrZeroScaledBigDecimalValidatorTest.java
@@ -0,0 +1,43 @@
+package it.aboutbits.springboot.toolbox.validation.validator;
+
+import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import jakarta.validation.Validation;
+import jakarta.validation.ValidatorFactory;
+import jakarta.validation.constraints.PositiveOrZero;
+import org.jspecify.annotations.NullMarked;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@NullMarked
+class PositiveOrZeroScaledBigDecimalValidatorTest {
+    private static final ValidatorFactory VALIDATOR_FACTORY = Validation.buildDefaultValidatorFactory();
+
+    record Sut(@PositiveOrZero ScaledBigDecimal value) {
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {0, 0.0000001, 1, 100_000_000.9999})
+    void valid_shouldSucceed(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isEmpty();
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {-1, -0.0000001})
+    void inValid_shouldFail(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isNotEmpty();
+    }
+}
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveScaledBigDecimalValidatorTest.java b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveScaledBigDecimalValidatorTest.java
new file mode 100644
index 0000000..71fe925
--- /dev/null
+++ b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/PositiveScaledBigDecimalValidatorTest.java
@@ -0,0 +1,43 @@
+package it.aboutbits.springboot.toolbox.validation.validator;
+
+import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
+import jakarta.validation.Validation;
+import jakarta.validation.ValidatorFactory;
+import jakarta.validation.constraints.Positive;
+import org.jspecify.annotations.NullMarked;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@NullMarked
+class PositiveScaledBigDecimalValidatorTest {
+    private static final ValidatorFactory VALIDATOR_FACTORY = Validation.buildDefaultValidatorFactory();
+
+    record Sut(@Positive ScaledBigDecimal value) {
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {0.0000001, 1, 100_000_000.9999})
+    void valid_shouldSucceed(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isEmpty();
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {-1, -0.0000001, 0})
+    void inValid_shouldFail(double doubleValue) {
+        var validator = VALIDATOR_FACTORY.getValidator();
+
+        var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
+
+        var violations = validator.validate(instance);
+
+        assertThat(violations).isNotEmpty();
+    }
+}
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/ScaledBigDecimalValidatorTest.java b/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/ScaledBigDecimalValidatorTest.java
deleted file mode 100644
index 814ca56..0000000
--- a/src/test/java/it/aboutbits/springboot/toolbox/validation/validator/ScaledBigDecimalValidatorTest.java
+++ /dev/null
@@ -1,200 +0,0 @@
-package it.aboutbits.springboot.toolbox.validation.validator;
-
-import it.aboutbits.springboot.toolbox.type.ScaledBigDecimal;
-import jakarta.validation.Validation;
-import jakarta.validation.ValidatorFactory;
-import jakarta.validation.constraints.Max;
-import jakarta.validation.constraints.Min;
-import jakarta.validation.constraints.Negative;
-import jakarta.validation.constraints.NegativeOrZero;
-import jakarta.validation.constraints.Positive;
-import jakarta.validation.constraints.PositiveOrZero;
-import org.junit.jupiter.api.Nested;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.ValueSource;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-public class ScaledBigDecimalValidatorTest {
-    private static final ValidatorFactory VALIDATOR_FACTORY = Validation.buildDefaultValidatorFactory();
-
-    @Nested
-    class PositiveConstraint {
-        record Sut(@Positive ScaledBigDecimal value) {
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {0.0000001, 1, 100_000_000.9999})
-        void valid_shouldSucceed(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isEmpty();
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {-1, -0.0000001, 0})
-        void inValid_shouldFail(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isNotEmpty();
-        }
-    }
-
-    @Nested
-    class PositiveOrZeroConstraint {
-        record Sut(@PositiveOrZero ScaledBigDecimal value) {
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {0, 0.0000001, 1, 100_000_000.9999})
-        void valid_shouldSucceed(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isEmpty();
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {-1, -0.0000001})
-        void inValid_shouldFail(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isNotEmpty();
-        }
-    }
-
-    @Nested
-    class NegativeConstraint {
-        record Sut(@Negative ScaledBigDecimal value) {
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {-1, -0.0000001})
-        void valid_shouldSucceed(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isEmpty();
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {0, 0.0000001, 1, 100_000_000.9999})
-        void inValid_shouldFail(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isNotEmpty();
-        }
-    }
-
-    @Nested
-    class NegativeOrZeroConstraint {
-        record Sut(@NegativeOrZero ScaledBigDecimal value) {
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {-1, -0.0000001, 0})
-        void valid_shouldSucceed(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isEmpty();
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {0.0000001, 1, 100_000_000.9999})
-        void inValid_shouldFail(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isNotEmpty();
-        }
-    }
-
-    @Nested
-    class MinConstraint {
-        record Sut(@Min(50) ScaledBigDecimal value) {
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {50, 50.0000001, 100_000_000.9999})
-        void valid_shouldSucceed(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isEmpty();
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {-1, -0.0000001, 0, 49, 49.999999})
-        void inValid_shouldFail(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isNotEmpty();
-        }
-    }
-
-    @Nested
-    class MaxConstraint {
-        record Sut(@Max(-50) ScaledBigDecimal value) {
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {-100_000_000.99999, -50.000001, -50})
-        void valid_shouldSucceed(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isEmpty();
-        }
-
-        @ParameterizedTest
-        @ValueSource(doubles = {-49.999999, -49, 0, 100_000_000})
-        void inValid_shouldFail(double doubleValue) {
-            var validator = VALIDATOR_FACTORY.getValidator();
-
-            var instance = new Sut(ScaledBigDecimal.valueOf(doubleValue));
-
-            var violations = validator.validate(instance);
-
-            assertThat(violations).isNotEmpty();
-        }
-    }
-}
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/web/SortParameterResolverTest.java b/src/test/java/it/aboutbits/springboot/toolbox/web/SortParameterResolverTest.java
index 7cd0aea..ab36a65 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/web/SortParameterResolverTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/web/SortParameterResolverTest.java
@@ -1,6 +1,7 @@
 package it.aboutbits.springboot.toolbox.web;
 
 import it.aboutbits.springboot.toolbox.parameter.SortParameter;
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -27,6 +28,7 @@
 import static org.mockito.Mockito.when;
 
 @ExtendWith(MockitoExtension.class)
+@NullMarked
 class SortParameterResolverTest {
     @Mock
     private MethodParameter methodParameter;
diff --git a/src/test/java/it/aboutbits/springboot/toolbox/web/response/PagedResponseTest.java b/src/test/java/it/aboutbits/springboot/toolbox/web/response/PagedResponseTest.java
index ae166f5..7fb8ae7 100644
--- a/src/test/java/it/aboutbits/springboot/toolbox/web/response/PagedResponseTest.java
+++ b/src/test/java/it/aboutbits/springboot/toolbox/web/response/PagedResponseTest.java
@@ -1,5 +1,6 @@
 package it.aboutbits.springboot.toolbox.web.response;
 
+import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.Test;
 import org.springframework.data.domain.PageImpl;
 import org.springframework.data.domain.PageRequest;
@@ -9,6 +10,7 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@NullMarked
 class PagedResponseTest {
     @Test
     void shouldReturnPagedResponseWithDataAndMeta_forSingleParameterOfMethod() {
diff --git a/src/test/resources/application.yml b/src/test/resources/application.yml
index 6a029c0..3d06cf2 100644
--- a/src/test/resources/application.yml
+++ b/src/test/resources/application.yml
@@ -1,6 +1,9 @@
 server:
   shutdown: graceful
 
+app:
+  name: Spring Boot Toolbox
+
 spring:
   lifecycle:
     timeout-per-shutdown-phase: 30s
diff --git a/src/test/resources/banner.txt b/src/test/resources/banner.txt
new file mode 100644
index 0000000..807c6ad
--- /dev/null
+++ b/src/test/resources/banner.txt
@@ -0,0 +1,7 @@
+     _    _                 _   ____  _ _
+    / \  | |__   ___  _   _| |_| __ )(_) |_ ___
+   / _ \ | '_ \ / _ \| | | | __|  _ \| | __/ __|
+  / ___ \| |_) | (_) | |_| | |_| |_) | | |_\__ \
+ /_/   \_\_.__/ \___/ \__,_|\__|____/|_|\__|___/
+ Spring Boot                        ${spring-boot.formatted-version}
+ :: ${app.name} ::