diff --git a/endpoints/clients.py b/endpoints/clients.py
index a079e934d451dd14a85251c4f94d6d9faa669058..74cf7717c85c1b7a4c4dd21377fca5c0c172e1b7 100644
--- a/endpoints/clients.py
+++ b/endpoints/clients.py
@@ -132,9 +132,9 @@ class ClientList(Resource):
         if errors: 
             abort(400, message=str(errors))
         
-        client = clients_file.find(args["client_id"])
+        client = self.clients_file.find(args["client_id"])
         if client:
             abort(403, message="Duplicate client id: {}".format(client_id))
         else:
-            client = clients_file.add(args)
+            client = self.clients_file.add(args)
         return client, 201