diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java
index 5eca273ce1e..6961bea23a1 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java
@@ -47,6 +47,7 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 
 public class Animal {
   public static final String JSON_PROPERTY_CLASS_NAME = "className";
+  @jakarta.annotation.Nonnull
   protected String className;
 
   public static final String JSON_PROPERTY_COLOR = "color";
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index f36713e575e..90608d1d29e 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -83,6 +83,7 @@ public class ParentWithNullable {
   }
 
   public static final String JSON_PROPERTY_TYPE = "type";
+  @jakarta.annotation.Nullable
   protected TypeEnum type;
 
   public static final String JSON_PROPERTY_NULLABLE_PROPERTY = "nullableProperty";
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java
index 734ca72ee17..29e7a29744b 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java
@@ -46,6 +46,7 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 
 public class Animal {
   public static final String JSON_PROPERTY_CLASS_NAME = "className";
+  @jakarta.annotation.Nonnull
   protected String className;
 
   public static final String JSON_PROPERTY_COLOR = "color";
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index e04601e3ba3..5c13648a7c2 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -82,6 +82,7 @@ public class ParentWithNullable {
   }
 
   public static final String JSON_PROPERTY_TYPE = "type";
+  @jakarta.annotation.Nullable
   protected TypeEnum type;
 
   public static final String JSON_PROPERTY_NULLABLE_PROPERTY = "nullableProperty";
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Animal.java
index 734ca72ee17..29e7a29744b 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Animal.java
@@ -46,6 +46,7 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 
 public class Animal {
   public static final String JSON_PROPERTY_CLASS_NAME = "className";
+  @jakarta.annotation.Nonnull
   protected String className;
 
   public static final String JSON_PROPERTY_COLOR = "color";
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index e04601e3ba3..5c13648a7c2 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -82,6 +82,7 @@ public class ParentWithNullable {
   }
 
   public static final String JSON_PROPERTY_TYPE = "type";
+  @jakarta.annotation.Nullable
   protected TypeEnum type;
 
   public static final String JSON_PROPERTY_NULLABLE_PROPERTY = "nullableProperty";