diff --git a/samples/client/petstore/python-asyncio/petstore_api/api_client.py b/samples/client/petstore/python-asyncio/petstore_api/api_client.py
index 470a9fda6245..132179b9b9c7 100644
--- a/samples/client/petstore/python-asyncio/petstore_api/api_client.py
+++ b/samples/client/petstore/python-asyncio/petstore_api/api_client.py
@@ -63,7 +63,7 @@ class ApiClient(object):
     _pool = None
 
     def __init__(self, configuration=None, header_name=None, header_value=None,
-                 cookie=None, pool_threads=1):
+                 cookie=None, pool_threads=None):
         if configuration is None:
             configuration = Configuration()
         self.configuration = configuration
diff --git a/samples/client/petstore/python-tornado/petstore_api/api_client.py b/samples/client/petstore/python-tornado/petstore_api/api_client.py
index a9bdacf1d2c0..fe0c3948a4dd 100644
--- a/samples/client/petstore/python-tornado/petstore_api/api_client.py
+++ b/samples/client/petstore/python-tornado/petstore_api/api_client.py
@@ -64,7 +64,7 @@ class ApiClient(object):
     _pool = None
 
     def __init__(self, configuration=None, header_name=None, header_value=None,
-                 cookie=None, pool_threads=1):
+                 cookie=None, pool_threads=None):
         if configuration is None:
             configuration = Configuration()
         self.configuration = configuration
diff --git a/samples/client/petstore/python/petstore_api/api_client.py b/samples/client/petstore/python/petstore_api/api_client.py
index a79d7ccf7425..a8acb32cf228 100644
--- a/samples/client/petstore/python/petstore_api/api_client.py
+++ b/samples/client/petstore/python/petstore_api/api_client.py
@@ -63,7 +63,7 @@ class ApiClient(object):
     _pool = None
 
     def __init__(self, configuration=None, header_name=None, header_value=None,
-                 cookie=None, pool_threads=1):
+                 cookie=None, pool_threads=None):
         if configuration is None:
             configuration = Configuration()
         self.configuration = configuration