diff --git a/oauth2client/client.py b/oauth2client/client.py
index 4cc3cda..6b580a0 100644
--- a/oauth2client/client.py
+++ b/oauth2client/client.py
@@ -554,7 +554,7 @@
             data['token_expiry'], EXPIRY_FORMAT)
       except:
         data['token_expiry'] = None
-    retval = OAuth2Credentials(
+    retval = cls(
         data['access_token'],
         data['client_id'],
         data['client_secret'],