diff --git a/.circleci/config.yml b/.circleci/config.yml
index 5f3112bd919..c83e86c971d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -122,7 +122,7 @@ jobs:
     steps:
       - command_build_and_test:
           jobId: "mvnCleanInstall"
-  testPythonClientSamples:
+  testPython38ClientSamples:
     docker:
       - image: python:3.8
     working_directory: ~/OpenAPITools/openapi-json-schema-generator
@@ -134,10 +134,23 @@ jobs:
       - checkout
       - command_docker_build_and_test:
           jobId: "testPythonClientSamples"
+  testPython39ClientSamples:
+    docker:
+      - image: python:3.9
+    working_directory: ~/OpenAPITools/openapi-json-schema-generator
+    shell: /bin/bash --login
+    environment:
+      CIRCLE_ARTIFACTS: /tmp/circleci-artifacts
+      CIRCLE_TEST_REPORTS: /tmp/circleci-test-results
+    steps:
+      - checkout
+      - command_docker_build_and_test:
+          jobId: "testPythonClientSamples"
 workflows:
   version: 2
   build:
     jobs:
       - ensureSamplesAndGeneratorDocsUpToDate
       - mvnCleanInstall
-      - testPythonClientSamples
+      - testPython38ClientSamples
+      - testPython39ClientSamples
diff --git a/samples/client/3_0_3_unit_test/python/src/unit_test_api/schemas/validation.py b/samples/client/3_0_3_unit_test/python/src/unit_test_api/schemas/validation.py
index 6c98ab116a8..5b40e210690 100644
--- a/samples/client/3_0_3_unit_test/python/src/unit_test_api/schemas/validation.py
+++ b/samples/client/3_0_3_unit_test/python/src/unit_test_api/schemas/validation.py
@@ -24,13 +24,7 @@
 
 from . import format, original_immutabledict
 
-_K = typing.TypeVar('_K')
-_V = typing.TypeVar('_V', covariant=True)
-
-
-class immutabledict(typing.Generic[_K, _V], original_immutabledict.immutabledict[_K, _V]):
-    # this class layer needed to not show init signature when making new instances
-    pass
+immutabledict = original_immutabledict.immutabledict
 
 
 @dataclasses.dataclass
@@ -172,7 +166,9 @@ def _get_class(
     elif isinstance(item_cls, type):
         return item_cls
     elif isinstance(item_cls, typing.ForwardRef):
-        return item_cls._evaluate(None, local_namespace)
+        if sys.version_info < (3, 9):
+            return item_cls._evaluate(None, local_namespace)
+        return item_cls._evaluate(None, local_namespace, set())
     raise ValueError('invalid class value passed in')
 
 
diff --git a/samples/client/3_0_3_unit_test/python/tox.ini b/samples/client/3_0_3_unit_test/python/tox.ini
index 86e3d2fbc19..a0162172546 100644
--- a/samples/client/3_0_3_unit_test/python/tox.ini
+++ b/samples/client/3_0_3_unit_test/python/tox.ini
@@ -1,5 +1,4 @@
 [tox]
-envlist = py38
 isolated_build = True
 
 [testenv]
diff --git a/samples/client/3_1_0_json_schema/python/src/json_schema_api/schemas/validation.py b/samples/client/3_1_0_json_schema/python/src/json_schema_api/schemas/validation.py
index e4d59817963..586a155e344 100644
--- a/samples/client/3_1_0_json_schema/python/src/json_schema_api/schemas/validation.py
+++ b/samples/client/3_1_0_json_schema/python/src/json_schema_api/schemas/validation.py
@@ -24,13 +24,7 @@
 
 from . import format, original_immutabledict
 
-_K = typing.TypeVar('_K')
-_V = typing.TypeVar('_V', covariant=True)
-
-
-class immutabledict(typing.Generic[_K, _V], original_immutabledict.immutabledict[_K, _V]):
-    # this class layer needed to not show init signature when making new instances
-    pass
+immutabledict = original_immutabledict.immutabledict
 
 
 @dataclasses.dataclass
@@ -172,7 +166,9 @@ def _get_class(
     elif isinstance(item_cls, type):
         return item_cls
     elif isinstance(item_cls, typing.ForwardRef):
-        return item_cls._evaluate(None, local_namespace)
+        if sys.version_info < (3, 9):
+            return item_cls._evaluate(None, local_namespace)
+        return item_cls._evaluate(None, local_namespace, set())
     raise ValueError('invalid class value passed in')
 
 
diff --git a/samples/client/3_1_0_json_schema/python/tox.ini b/samples/client/3_1_0_json_schema/python/tox.ini
index 283695fea66..f29d5884e07 100644
--- a/samples/client/3_1_0_json_schema/python/tox.ini
+++ b/samples/client/3_1_0_json_schema/python/tox.ini
@@ -1,5 +1,4 @@
 [tox]
-envlist = py38
 isolated_build = True
 
 [testenv]
diff --git a/samples/client/openapi_features/nonCompliantUseDiscriminatorIfCompositionFails/python/src/this_package/schemas/validation.py b/samples/client/openapi_features/nonCompliantUseDiscriminatorIfCompositionFails/python/src/this_package/schemas/validation.py
index e876722045c..ad4bac5f15b 100644
--- a/samples/client/openapi_features/nonCompliantUseDiscriminatorIfCompositionFails/python/src/this_package/schemas/validation.py
+++ b/samples/client/openapi_features/nonCompliantUseDiscriminatorIfCompositionFails/python/src/this_package/schemas/validation.py
@@ -24,13 +24,7 @@
 
 from . import format, original_immutabledict
 
-_K = typing.TypeVar('_K')
-_V = typing.TypeVar('_V', covariant=True)
-
-
-class immutabledict(typing.Generic[_K, _V], original_immutabledict.immutabledict[_K, _V]):
-    # this class layer needed to not show init signature when making new instances
-    pass
+immutabledict = original_immutabledict.immutabledict
 
 
 @dataclasses.dataclass
@@ -184,7 +178,9 @@ def _get_class(
     elif isinstance(item_cls, type):
         return item_cls
     elif isinstance(item_cls, typing.ForwardRef):
-        return item_cls._evaluate(None, local_namespace)
+        if sys.version_info < (3, 9):
+            return item_cls._evaluate(None, local_namespace)
+        return item_cls._evaluate(None, local_namespace, set())
     raise ValueError('invalid class value passed in')
 
 
diff --git a/samples/client/openapi_features/nonCompliantUseDiscriminatorIfCompositionFails/python/tox.ini b/samples/client/openapi_features/nonCompliantUseDiscriminatorIfCompositionFails/python/tox.ini
index 7bd1406a8c5..f942843237d 100644
--- a/samples/client/openapi_features/nonCompliantUseDiscriminatorIfCompositionFails/python/tox.ini
+++ b/samples/client/openapi_features/nonCompliantUseDiscriminatorIfCompositionFails/python/tox.ini
@@ -1,5 +1,4 @@
 [tox]
-envlist = py38
 isolated_build = True
 
 [testenv]
diff --git a/samples/client/openapi_features/security/python/src/this_package/schemas/validation.py b/samples/client/openapi_features/security/python/src/this_package/schemas/validation.py
index 94f9b5eb782..2c0ea36f61d 100644
--- a/samples/client/openapi_features/security/python/src/this_package/schemas/validation.py
+++ b/samples/client/openapi_features/security/python/src/this_package/schemas/validation.py
@@ -24,13 +24,7 @@
 
 from . import format, original_immutabledict
 
-_K = typing.TypeVar('_K')
-_V = typing.TypeVar('_V', covariant=True)
-
-
-class immutabledict(typing.Generic[_K, _V], original_immutabledict.immutabledict[_K, _V]):
-    # this class layer needed to not show init signature when making new instances
-    pass
+immutabledict = original_immutabledict.immutabledict
 
 
 @dataclasses.dataclass
@@ -172,7 +166,9 @@ def _get_class(
     elif isinstance(item_cls, type):
         return item_cls
     elif isinstance(item_cls, typing.ForwardRef):
-        return item_cls._evaluate(None, local_namespace)
+        if sys.version_info < (3, 9):
+            return item_cls._evaluate(None, local_namespace)
+        return item_cls._evaluate(None, local_namespace, set())
     raise ValueError('invalid class value passed in')
 
 
diff --git a/samples/client/openapi_features/security/python/tox.ini b/samples/client/openapi_features/security/python/tox.ini
index 7bd1406a8c5..f942843237d 100644
--- a/samples/client/openapi_features/security/python/tox.ini
+++ b/samples/client/openapi_features/security/python/tox.ini
@@ -1,5 +1,4 @@
 [tox]
-envlist = py38
 isolated_build = True
 
 [testenv]
diff --git a/samples/client/petstore/python/src/petstore_api/schemas/validation.py b/samples/client/petstore/python/src/petstore_api/schemas/validation.py
index dbdc99d10b5..1bc6543b9ce 100644
--- a/samples/client/petstore/python/src/petstore_api/schemas/validation.py
+++ b/samples/client/petstore/python/src/petstore_api/schemas/validation.py
@@ -24,13 +24,7 @@
 
 from . import format, original_immutabledict
 
-_K = typing.TypeVar('_K')
-_V = typing.TypeVar('_V', covariant=True)
-
-
-class immutabledict(typing.Generic[_K, _V], original_immutabledict.immutabledict[_K, _V]):
-    # this class layer needed to not show init signature when making new instances
-    pass
+immutabledict = original_immutabledict.immutabledict
 
 
 @dataclasses.dataclass
@@ -172,7 +166,9 @@ def _get_class(
     elif isinstance(item_cls, type):
         return item_cls
     elif isinstance(item_cls, typing.ForwardRef):
-        return item_cls._evaluate(None, local_namespace)
+        if sys.version_info < (3, 9):
+            return item_cls._evaluate(None, local_namespace)
+        return item_cls._evaluate(None, local_namespace, set())
     raise ValueError('invalid class value passed in')
 
 
diff --git a/samples/client/petstore/python/tox.ini b/samples/client/petstore/python/tox.ini
index 0bcd8dd9169..e75b80f1df7 100644
--- a/samples/client/petstore/python/tox.ini
+++ b/samples/client/petstore/python/tox.ini
@@ -1,5 +1,4 @@
 [tox]
-envlist = py38
 isolated_build = True
 
 [testenv]
diff --git a/src/main/resources/python/schemas/validation.hbs b/src/main/resources/python/schemas/validation.hbs
index 65aebf15a04..012159c5804 100644
--- a/src/main/resources/python/schemas/validation.hbs
+++ b/src/main/resources/python/schemas/validation.hbs
@@ -19,13 +19,7 @@ from {{packageName}}.configurations import schema_configuration
 
 from . import format, original_immutabledict
 
-_K = typing.TypeVar('_K')
-_V = typing.TypeVar('_V', covariant=True)
-
-
-class immutabledict(typing.Generic[_K, _V], original_immutabledict.immutabledict[_K, _V]):
-    # this class layer needed to not show init signature when making new instances
-    pass
+immutabledict = original_immutabledict.immutabledict
 
 
 @dataclasses.dataclass
@@ -183,7 +177,9 @@ def _get_class(
     elif isinstance(item_cls, type):
         return item_cls
     elif isinstance(item_cls, typing.ForwardRef):
-        return item_cls._evaluate(None, local_namespace)
+        if sys.version_info < (3, 9):
+            return item_cls._evaluate(None, local_namespace)
+        return item_cls._evaluate(None, local_namespace, set())
     raise ValueError('invalid class value passed in')
 
 
diff --git a/src/main/resources/python/tox.hbs b/src/main/resources/python/tox.hbs
index 5f9a3a9dca2..9e38a0043c1 100644
--- a/src/main/resources/python/tox.hbs
+++ b/src/main/resources/python/tox.hbs
@@ -1,5 +1,4 @@
 [tox]
-envlist = py38
 isolated_build = True
 
 [testenv]