diff --git a/swagger_templates/python/api.mustache b/swagger_templates/python/api.mustache
index 12ec03c..b68bb1f 100644
--- a/swagger_templates/python/api.mustache
+++ b/swagger_templates/python/api.mustache
@@ -33,16 +33,16 @@ class {{classname}}(object):
         {{{notes}}}  # noqa: E501
 {{/notes}}
         This method makes a synchronous HTTP request by default. To make an
-        asynchronous HTTP request, please pass async=True
+        asynchronous HTTP request, please pass async_req=True
 {{#sortParamsByRequiredFlag}}
-        >>> thread = api.{{operationId}}({{#allParams}}{{#required}}{{paramName}}, {{/required}}{{/allParams}}async=True)
+        >>> thread = api.{{operationId}}({{#allParams}}{{#required}}{{paramName}}, {{/required}}{{/allParams}}async_req=True)
 {{/sortParamsByRequiredFlag}}
 {{^sortParamsByRequiredFlag}}
-        >>> thread = api.{{operationId}}({{#allParams}}{{#required}}{{paramName}}={{paramName}}_value, {{/required}}{{/allParams}}async=True)
+        >>> thread = api.{{operationId}}({{#allParams}}{{#required}}{{paramName}}={{paramName}}_value, {{/required}}{{/allParams}}async_req=True)
 {{/sortParamsByRequiredFlag}}
         >>> result = thread.get()
 
-        :param async bool
+        :param async_req bool
 {{#allParams}}
         :param {{dataType}} {{paramName}}:{{#description}} {{{description}}}{{/description}}{{#required}} (required){{/required}}{{#optional}}(optional){{/optional}}
 {{/allParams}}
@@ -51,7 +51,7 @@ class {{classname}}(object):
                  returns the request thread.
         """
         kwargs['_return_http_data_only'] = True
-        if kwargs.get('async'):
+        if kwargs.get('async_req'):
             return self.{{operationId}}_with_http_info({{#sortParamsByRequiredFlag}}{{#allParams}}{{#required}}{{paramName}}, {{/required}}{{/allParams}}{{/sortParamsByRequiredFlag}}**kwargs)  # noqa: E501
         else:
             (data) = self.{{operationId}}_with_http_info({{#sortParamsByRequiredFlag}}{{#allParams}}{{#required}}{{paramName}}, {{/required}}{{/allParams}}{{/sortParamsByRequiredFlag}}**kwargs)  # noqa: E501
@@ -64,16 +64,16 @@ class {{classname}}(object):
         {{{notes}}}  # noqa: E501
 {{/notes}}
         This method makes a synchronous HTTP request by default. To make an
-        asynchronous HTTP request, please pass async=True
+        asynchronous HTTP request, please pass async_req=True
 {{#sortParamsByRequiredFlag}}
-        >>> thread = api.{{operationId}}_with_http_info({{#allParams}}{{#required}}{{paramName}}, {{/required}}{{/allParams}}async=True)
+        >>> thread = api.{{operationId}}_with_http_info({{#allParams}}{{#required}}{{paramName}}, {{/required}}{{/allParams}}async_req=True)
 {{/sortParamsByRequiredFlag}}
 {{^sortParamsByRequiredFlag}}
-        >>> thread = api.{{operationId}}_with_http_info({{#allParams}}{{#required}}{{paramName}}={{paramName}}_value, {{/required}}{{/allParams}}async=True)
+        >>> thread = api.{{operationId}}_with_http_info({{#allParams}}{{#required}}{{paramName}}={{paramName}}_value, {{/required}}{{/allParams}}async_req=True)
 {{/sortParamsByRequiredFlag}}
         >>> result = thread.get()
 
-        :param async bool
+        :param async_req bool
 {{#allParams}}
         :param {{dataType}} {{paramName}}:{{#description}} {{{description}}}{{/description}}{{#required}} (required){{/required}}{{#optional}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/optional}}
 {{/allParams}}
@@ -83,7 +83,7 @@ class {{classname}}(object):
         """
 
         all_params = [{{#allParams}}'{{paramName}}'{{#hasMore}}, {{/hasMore}}{{/allParams}}]  # noqa: E501
-        all_params.append('async')
+        all_params.append('async_req')
         all_params.append('_return_http_data_only')
         all_params.append('_preload_content')
         all_params.append('_request_timeout')
@@ -212,7 +212,7 @@ class {{classname}}(object):
             files=local_var_files,
             response_type={{#returnType}}'{{returnType}}'{{/returnType}}{{^returnType}}None{{/returnType}},  # noqa: E501
             auth_settings=auth_settings,
-            async=params.get('async'),
+            async_req=params.get('async_req'),
             _return_http_data_only=params.get('_return_http_data_only'),
             _preload_content=params.get('_preload_content', True),
             _request_timeout=params.get('_request_timeout'),
diff --git a/swagger_templates/python/api_client.mustache b/swagger_templates/python/api_client.mustache
index 7fccaa0..78b002c 100644
--- a/swagger_templates/python/api_client.mustache
+++ b/swagger_templates/python/api_client.mustache
@@ -98,7 +98,7 @@ class ApiClient(object):
     {{#tornado}}
     @tornado.gen.coroutine
     {{/tornado}}
-    {{#asyncio}}async {{/asyncio}}def __call_api(
+    {{#asyncio}}async_req {{/asyncio}}def __call_api(
             self, resource_path, method, path_params=None,
             query_params=None, header_params=None, body=None, post_params=None,
             files=None, response_type=None, auth_settings=None,
@@ -304,12 +304,12 @@ class ApiClient(object):
     def call_api(self, resource_path, method,
                  path_params=None, query_params=None, header_params=None,
                  body=None, post_params=None, files=None,
-                 response_type=None, auth_settings=None, async=None,
+                 response_type=None, auth_settings=None, async_req=None,
                  _return_http_data_only=None, collection_formats=None,
                  _preload_content=True, _request_timeout=None):
         """Makes the HTTP request (synchronous) and returns deserialized data.
 
-        To make an async request, set the async parameter.
+        To make an async request, set the async_req parameter.
 
         :param resource_path: Path to method endpoint.
         :param method: Method to call.
@@ -324,7 +324,7 @@ class ApiClient(object):
         :param response: Response data type.
         :param files dict: key -> filename, value -> filepath,
             for `multipart/form-data`.
-        :param async bool: execute request asynchronously
+        :param async_req bool: execute request asynchronously
         :param _return_http_data_only: response data without head status code
                                        and headers
         :param collection_formats: dict of collection formats for path, query,
@@ -337,13 +337,13 @@ class ApiClient(object):
                                  timeout. It can also be a pair (tuple) of
                                  (connection, read) timeouts.
         :return:
-            If async parameter is True,
+            If async_req parameter is True,
             the request will be called asynchronously.
             The method will return the request thread.
-            If parameter async is False or missing,
+            If parameter async_req is False or missing,
             then the method will return the response directly.
         """
-        if not async:
+        if not async_req:
             return self.__call_api(resource_path, method,
                                    path_params, query_params, header_params,
                                    body, post_params, files,