diff --git a/modules/openapi-generator/src/main/resources/python-fastapi/model_anyof.mustache b/modules/openapi-generator/src/main/resources/python-fastapi/model_anyof.mustache
index 0d575011b26..b145f73ad13 100644
--- a/modules/openapi-generator/src/main/resources/python-fastapi/model_anyof.mustache
+++ b/modules/openapi-generator/src/main/resources/python-fastapi/model_anyof.mustache
@@ -176,7 +176,8 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
         if callable(to_json):
             return self.actual_instance.to_dict()
         else:
-            return json.dumps(self.actual_instance)
+            # primitive type
+            return self.actual_instance
 
     def to_str(self) -> str:
         """Returns the string representation of the actual instance"""
diff --git a/modules/openapi-generator/src/main/resources/python-pydantic-v1/model_anyof.mustache b/modules/openapi-generator/src/main/resources/python-pydantic-v1/model_anyof.mustache
index adec7c41868..e76bd81c46d 100644
--- a/modules/openapi-generator/src/main/resources/python-pydantic-v1/model_anyof.mustache
+++ b/modules/openapi-generator/src/main/resources/python-pydantic-v1/model_anyof.mustache
@@ -166,7 +166,8 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
         if callable(to_json):
             return self.actual_instance.to_dict()
         else:
-            return json.dumps(self.actual_instance)
+            # primitive type
+            return self.actual_instance
 
     def to_str(self) -> str:
         """Returns the string representation of the actual instance"""
diff --git a/samples/openapi3/client/petstore/python-pydantic-v1-aiohttp/petstore_api/models/any_of_color.py b/samples/openapi3/client/petstore/python-pydantic-v1-aiohttp/petstore_api/models/any_of_color.py
index 60dbbe6dd7e..d1ed38dc9b1 100644
--- a/samples/openapi3/client/petstore/python-pydantic-v1-aiohttp/petstore_api/models/any_of_color.py
+++ b/samples/openapi3/client/petstore/python-pydantic-v1-aiohttp/petstore_api/models/any_of_color.py
@@ -146,7 +146,8 @@ class AnyOfColor(BaseModel):
         if callable(to_json):
             return self.actual_instance.to_dict()
         else:
-            return json.dumps(self.actual_instance)
+            # primitive type
+            return self.actual_instance
 
     def to_str(self) -> str:
         """Returns the string representation of the actual instance"""
diff --git a/samples/openapi3/client/petstore/python-pydantic-v1-aiohttp/petstore_api/models/any_of_pig.py b/samples/openapi3/client/petstore/python-pydantic-v1-aiohttp/petstore_api/models/any_of_pig.py
index 1254f6789a8..018d892467b 100644
--- a/samples/openapi3/client/petstore/python-pydantic-v1-aiohttp/petstore_api/models/any_of_pig.py
+++ b/samples/openapi3/client/petstore/python-pydantic-v1-aiohttp/petstore_api/models/any_of_pig.py
@@ -125,7 +125,8 @@ class AnyOfPig(BaseModel):
         if callable(to_json):
             return self.actual_instance.to_dict()
         else:
-            return json.dumps(self.actual_instance)
+            # primitive type
+            return self.actual_instance
 
     def to_str(self) -> str:
         """Returns the string representation of the actual instance"""
diff --git a/samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/any_of_color.py b/samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/any_of_color.py
index 60dbbe6dd7e..d1ed38dc9b1 100644
--- a/samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/any_of_color.py
+++ b/samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/any_of_color.py
@@ -146,7 +146,8 @@ class AnyOfColor(BaseModel):
         if callable(to_json):
             return self.actual_instance.to_dict()
         else:
-            return json.dumps(self.actual_instance)
+            # primitive type
+            return self.actual_instance
 
     def to_str(self) -> str:
         """Returns the string representation of the actual instance"""
diff --git a/samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/any_of_pig.py b/samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/any_of_pig.py
index 1254f6789a8..018d892467b 100644
--- a/samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/any_of_pig.py
+++ b/samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/any_of_pig.py
@@ -125,7 +125,8 @@ class AnyOfPig(BaseModel):
         if callable(to_json):
             return self.actual_instance.to_dict()
         else:
-            return json.dumps(self.actual_instance)
+            # primitive type
+            return self.actual_instance
 
     def to_str(self) -> str:
         """Returns the string representation of the actual instance"""
diff --git a/samples/openapi3/client/petstore/python-pydantic-v1/tests/test_model.py b/samples/openapi3/client/petstore/python-pydantic-v1/tests/test_model.py
index b66a414f913..ce84e0b035f 100644
--- a/samples/openapi3/client/petstore/python-pydantic-v1/tests/test_model.py
+++ b/samples/openapi3/client/petstore/python-pydantic-v1/tests/test_model.py
@@ -177,7 +177,7 @@ class ModelTests(unittest.TestCase):
         except ValueError as e:
             self.assertTrue("ensure this value is less than or equal to 255" in str(e))
 
-        # test from_josn
+        # test from_json
         json_str = '[12,34,56]'
         p = petstore_api.AnyOfColor.from_json(json_str)
         self.assertEqual(p.actual_instance, [12, 34,56])
@@ -187,6 +187,28 @@ class ModelTests(unittest.TestCase):
         except ValueError as e:
             self.assertTrue("ensure this value is less than or equal to 255" in str(e))
 
+         # test from_json, schema 3
+        json_str = '"#123456"'
+        p = petstore_api.AnyOfColor.from_json(json_str)
+        self.assertIsInstance(p.actual_instance, str)
+        self.assertEqual(p.actual_instance, '#123456')
+
+        # test to_json, schema 3
+        p = petstore_api.AnyOfColor(actual_instance='#123456')
+        self.assertEqual(p.to_json(), '"#123456"')
+
+         # test from_dict, schema 3
+        obj = '#123456'
+        p = petstore_api.AnyOfColor.from_dict(obj)
+        self.assertIsInstance(p.actual_instance, str)
+        self.assertEqual(p.actual_instance, '#123456')
+
+        # test to_dict, schema 3
+        p = petstore_api.AnyOfColor(actual_instance='#123456')
+        self.assertEqual(p.to_dict(), '#123456')
+        p = petstore_api.AnyOfColor.from_dict(p.to_dict())
+        self.assertEqual(p.actual_instance, '#123456')
+
     def test_oneOf(self):
         # test new Pig
         bp = petstore_api.BasquePig.from_dict({"className": "BasquePig", "color": "red"})
@@ -300,6 +322,9 @@ class ModelTests(unittest.TestCase):
                 "  DanishPig expected dict not int (type=type_error)")
             self.assertEqual(str(e), error_message)
 
+        # test to_dict
+        self.assertEqual(p.to_dict(), {'className': 'BasquePig', 'color': 'red'})
+
         # test to_json
         self.assertEqual(p.to_json(), '{"className": "BasquePig", "color": "red"}')