diff --git a/modules/openapi-generator/src/main/resources/python/api_client.mustache b/modules/openapi-generator/src/main/resources/python/api_client.mustache
index aad33bcc06cb..a4b00138b60c 100644
--- a/modules/openapi-generator/src/main/resources/python/api_client.mustache
+++ b/modules/openapi-generator/src/main/resources/python/api_client.mustache
@@ -412,12 +412,12 @@ class ApiClient:
                 data = json.loads(response_text)
             except ValueError:
                 data = response_text
-        elif content_type.startswith("application/json"):
+        elif re.match(r'^application/(json|[\w!#$&.+-^_]+\+json)\s*(;|$)', content_type, re.IGNORECASE):
             if response_text == "":
                 data = ""
             else:
                 data = json.loads(response_text)
-        elif content_type.startswith("text/plain"):
+        elif re.match(r'^text/plain\s*(;|$)', content_type, re.IGNORECASE):
             data = response_text
         else:
             raise ApiException(
diff --git a/samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent/openapi_client/api_client.py b/samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent/openapi_client/api_client.py
index c6fa28de3197..d1c19f8f7ebe 100644
--- a/samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent/openapi_client/api_client.py
+++ b/samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent/openapi_client/api_client.py
@@ -405,12 +405,12 @@ def deserialize(self, response_text: str, response_type: str, content_type: Opti
                 data = json.loads(response_text)
             except ValueError:
                 data = response_text
-        elif content_type.startswith("application/json"):
+        elif re.match(r'^application/(json|[\w!#$&.+-^_]+\+json)\s*(;|$)', content_type, re.IGNORECASE):
             if response_text == "":
                 data = ""
             else:
                 data = json.loads(response_text)
-        elif content_type.startswith("text/plain"):
+        elif re.match(r'^text/plain\s*(;|$)', content_type, re.IGNORECASE):
             data = response_text
         else:
             raise ApiException(
diff --git a/samples/client/echo_api/python/openapi_client/api_client.py b/samples/client/echo_api/python/openapi_client/api_client.py
index c6fa28de3197..d1c19f8f7ebe 100644
--- a/samples/client/echo_api/python/openapi_client/api_client.py
+++ b/samples/client/echo_api/python/openapi_client/api_client.py
@@ -405,12 +405,12 @@ def deserialize(self, response_text: str, response_type: str, content_type: Opti
                 data = json.loads(response_text)
             except ValueError:
                 data = response_text
-        elif content_type.startswith("application/json"):
+        elif re.match(r'^application/(json|[\w!#$&.+-^_]+\+json)\s*(;|$)', content_type, re.IGNORECASE):
             if response_text == "":
                 data = ""
             else:
                 data = json.loads(response_text)
-        elif content_type.startswith("text/plain"):
+        elif re.match(r'^text/plain\s*(;|$)', content_type, re.IGNORECASE):
             data = response_text
         else:
             raise ApiException(
diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/api_client.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/api_client.py
index db57dd1827b6..40a6113a71f8 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/api_client.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/api_client.py
@@ -407,12 +407,12 @@ def deserialize(self, response_text: str, response_type: str, content_type: Opti
                 data = json.loads(response_text)
             except ValueError:
                 data = response_text
-        elif content_type.startswith("application/json"):
+        elif re.match(r'^application/(json|[\w!#$&.+-^_]+\+json)\s*(;|$)', content_type, re.IGNORECASE):
             if response_text == "":
                 data = ""
             else:
                 data = json.loads(response_text)
-        elif content_type.startswith("text/plain"):
+        elif re.match(r'^text/plain\s*(;|$)', content_type, re.IGNORECASE):
             data = response_text
         else:
             raise ApiException(
diff --git a/samples/openapi3/client/petstore/python/petstore_api/api_client.py b/samples/openapi3/client/petstore/python/petstore_api/api_client.py
index cb831d0de813..3dcda1b2baff 100755
--- a/samples/openapi3/client/petstore/python/petstore_api/api_client.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/api_client.py
@@ -404,12 +404,12 @@ def deserialize(self, response_text: str, response_type: str, content_type: Opti
                 data = json.loads(response_text)
             except ValueError:
                 data = response_text
-        elif content_type.startswith("application/json"):
+        elif re.match(r'^application/(json|[\w!#$&.+-^_]+\+json)\s*(;|$)', content_type, re.IGNORECASE):
             if response_text == "":
                 data = ""
             else:
                 data = json.loads(response_text)
-        elif content_type.startswith("text/plain"):
+        elif re.match(r'^text/plain\s*(;|$)', content_type, re.IGNORECASE):
             data = response_text
         else:
             raise ApiException(
diff --git a/samples/openapi3/client/petstore/python/tests/test_deserialization.py b/samples/openapi3/client/petstore/python/tests/test_deserialization.py
index 11b2955015ac..0ebfa1bb30a0 100644
--- a/samples/openapi3/client/petstore/python/tests/test_deserialization.py
+++ b/samples/openapi3/client/petstore/python/tests/test_deserialization.py
@@ -301,3 +301,35 @@ def test_deserialize_animal(self):
         self.assertEqual(deserialized.class_name, "Cat")
         self.assertEqual(deserialized.declawed, True)
         self.assertEqual(deserialized.to_json(), '{"className": "Cat", "color": "red", "declawed": true}')
+
+    def test_deserialize_content_type(self):
+
+        response = json.dumps({"a": "a"})
+        
+        deserialized = self.deserialize(response, "Dict[str, str]", 'application/json')
+        self.assertTrue(isinstance(deserialized, dict))
+
+        
+        deserialized = self.deserialize(response, "Dict[str, str]", 'application/vnd.api+json')
+        self.assertTrue(isinstance(deserialized, dict))
+
+
+        deserialized = self.deserialize(response, "Dict[str, str]", 'application/json; charset=utf-8')
+        self.assertTrue(isinstance(deserialized, dict))
+
+        deserialized = self.deserialize(response, "Dict[str, str]", 'application/vnd.api+json; charset=utf-8')
+        self.assertTrue(isinstance(deserialized, dict))
+
+        deserialized = self.deserialize(response, "str", 'text/plain')
+        self.assertTrue(isinstance(deserialized, str))
+        
+        deserialized = self.deserialize(response, "Dict[str, str]", 'APPLICATION/JSON')
+        self.assertTrue(isinstance(deserialized, dict))
+        
+        with self.assertRaises(petstore_api.ApiException) as cm:
+            deserialized = self.deserialize(response, "str", 'text/html')
+
+        with self.assertRaises(petstore_api.ApiException) as cm:
+            deserialized = self.deserialize(response, "Dict[str, str]", 'application/jsonnnnn')
+        
+