diff --git a/bin/configs/java-microprofile-rest-client-3.0-jackson.yaml b/bin/configs/java-microprofile-rest-client-3.0-jackson.yaml
index 7ffcc1cdcb85..2cf93a6d63a1 100644
--- a/bin/configs/java-microprofile-rest-client-3.0-jackson.yaml
+++ b/bin/configs/java-microprofile-rest-client-3.0-jackson.yaml
@@ -10,3 +10,4 @@ additionalProperties:
   microprofileRestClientVersion: "3.0"
   hideGenerationTimestamp: true
   useReflectionEqualsHashCode: true
+  openApiNullable: false
diff --git a/bin/configs/java-microprofile-rest-client-3.0.yaml b/bin/configs/java-microprofile-rest-client-3.0.yaml
index 0963a49c9d28..56689e70ba91 100644
--- a/bin/configs/java-microprofile-rest-client-3.0.yaml
+++ b/bin/configs/java-microprofile-rest-client-3.0.yaml
@@ -7,3 +7,4 @@ additionalProperties:
   artifactId: microprofile-rest-client-3
   configKey: petstore
   microprofileRestClientVersion: "3.0"
+  openApiNullable: false
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 38b3720a3b26..4c315942c2c1 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -25,7 +25,6 @@
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
 import org.openapitools.client.model.ParentWithNullable;
-import org.openapitools.jackson.nullable.JsonNullable;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 
@@ -74,22 +73,11 @@ public boolean equals(Object o) {
     return EqualsBuilder.reflectionEquals(this, o, false, null, true);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return HashCodeBuilder.reflectionHashCode(this);
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumTest.java
index b371a373809d..c896035c6e69 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -25,10 +25,6 @@
 import org.openapitools.client.model.OuterEnumDefaultValue;
 import org.openapitools.client.model.OuterEnumInteger;
 import org.openapitools.client.model.OuterEnumIntegerDefaultValue;
-import org.openapitools.jackson.nullable.JsonNullable;
-import com.fasterxml.jackson.annotation.JsonIgnore;
-import org.openapitools.jackson.nullable.JsonNullable;
-import java.util.NoSuchElementException;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 
@@ -403,22 +399,11 @@ public boolean equals(Object o) {
     return EqualsBuilder.reflectionEquals(this, o, false, null, true);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return HashCodeBuilder.reflectionHashCode(this);
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 3185667c428b..faeae0f51c2d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -21,10 +21,6 @@
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
-import org.openapitools.jackson.nullable.JsonNullable;
-import com.fasterxml.jackson.annotation.JsonIgnore;
-import org.openapitools.jackson.nullable.JsonNullable;
-import java.util.NoSuchElementException;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 
@@ -70,22 +66,11 @@ public boolean equals(Object o) {
     return EqualsBuilder.reflectionEquals(this, o, false, null, true);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return HashCodeBuilder.reflectionHashCode(this);
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NullableClass.java
index 0483fe250ba1..059c3597bcb0 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -28,10 +28,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.openapitools.jackson.nullable.JsonNullable;
-import com.fasterxml.jackson.annotation.JsonIgnore;
-import org.openapitools.jackson.nullable.JsonNullable;
-import java.util.NoSuchElementException;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 
@@ -441,22 +437,11 @@ public boolean equals(Object o) {
     return EqualsBuilder.reflectionEquals(this, o, false, null, true);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return HashCodeBuilder.reflectionHashCode(this);
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 574ba07f534d..657f266e6db5 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -24,10 +24,6 @@
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonValue;
-import org.openapitools.jackson.nullable.JsonNullable;
-import com.fasterxml.jackson.annotation.JsonIgnore;
-import org.openapitools.jackson.nullable.JsonNullable;
-import java.util.NoSuchElementException;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 
@@ -140,22 +136,11 @@ public boolean equals(Object o) {
     return EqualsBuilder.reflectionEquals(this, o, false, null, true);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return HashCodeBuilder.reflectionHashCode(this);
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 1536a7dcf959..078676fd7cd4 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -15,7 +15,6 @@
 import java.util.Objects;
 import java.util.Arrays;
 import org.openapitools.client.model.ParentWithNullable;
-import org.openapitools.jackson.nullable.JsonNullable;
 import java.lang.reflect.Type;
 import jakarta.json.bind.annotation.JsonbTypeDeserializer;
 import jakarta.json.bind.annotation.JsonbTypeSerializer;
@@ -69,22 +68,11 @@ public boolean equals(Object o) {
         super.equals(o);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return Objects.hash(otherProperty, super.hashCode());
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumTest.java
index 05ccde5fdc7e..c5922a925d9b 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -18,7 +18,6 @@
 import org.openapitools.client.model.OuterEnumDefaultValue;
 import org.openapitools.client.model.OuterEnumInteger;
 import org.openapitools.client.model.OuterEnumIntegerDefaultValue;
-import org.openapitools.jackson.nullable.JsonNullable;
 import java.lang.reflect.Type;
 import jakarta.json.bind.annotation.JsonbTypeDeserializer;
 import jakarta.json.bind.annotation.JsonbTypeSerializer;
@@ -407,22 +406,11 @@ public boolean equals(Object o) {
         Objects.equals(this.outerEnumIntegerDefaultValue, enumTest.outerEnumIntegerDefaultValue);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return Objects.hash(enumString, enumStringRequired, enumInteger, enumNumber, outerEnum, outerEnumInteger, outerEnumDefaultValue, outerEnumIntegerDefaultValue);
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index dcf27d41154d..f565e8727dbb 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -14,7 +14,6 @@
 
 import java.util.Objects;
 import java.util.Arrays;
-import org.openapitools.jackson.nullable.JsonNullable;
 import java.lang.reflect.Type;
 import jakarta.json.bind.annotation.JsonbTypeDeserializer;
 import jakarta.json.bind.annotation.JsonbTypeSerializer;
@@ -70,22 +69,11 @@ public boolean equals(Object o) {
     return Objects.equals(this.nullableMessage, healthCheckResult.nullableMessage);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return Objects.hash(nullableMessage);
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NullableClass.java
index 87c7998164e2..93130350813f 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -21,7 +21,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.openapitools.jackson.nullable.JsonNullable;
 import java.lang.reflect.Type;
 import jakarta.json.bind.annotation.JsonbTypeDeserializer;
 import jakarta.json.bind.annotation.JsonbTypeSerializer;
@@ -387,22 +386,11 @@ public boolean equals(Object o) {
         super.equals(o);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return Objects.hash(integerProp, numberProp, booleanProp, stringProp, dateProp, datetimeProp, arrayNullableProp, arrayAndItemsNullableProp, arrayItemsNullable, objectNullableProp, objectAndItemsNullableProp, objectItemsNullable, super.hashCode());
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index c71afa7b1702..7eace49a0c7b 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -14,7 +14,6 @@
 
 import java.util.Objects;
 import java.util.Arrays;
-import org.openapitools.jackson.nullable.JsonNullable;
 import java.lang.reflect.Type;
 import jakarta.json.bind.annotation.JsonbTypeDeserializer;
 import jakarta.json.bind.annotation.JsonbTypeSerializer;
@@ -135,22 +134,11 @@ public boolean equals(Object o) {
         Objects.equals(this.nullableProperty, parentWithNullable.nullableProperty);
   }
 
-  private static <T> boolean equalsNullable(JsonNullable<T> a, JsonNullable<T> b) {
-    return a == b || (a != null && b != null && a.isPresent() && b.isPresent() && Objects.deepEquals(a.get(), b.get()));
-  }
-
   @Override
   public int hashCode() {
     return Objects.hash(type, nullableProperty);
   }
 
-  private static <T> int hashCodeNullable(JsonNullable<T> a) {
-    if (a == null) {
-      return 1;
-    }
-    return a.isPresent() ? Arrays.deepHashCode(new Object[]{a.get()}) : 31;
-  }
-
   /**
    * Create a string representation of this pojo.
    */