diff --git a/openstack/common/rpc/impl_fake.py b/openstack/common/rpc/impl_fake.py
index d526a48d7..9b168edc4 100644
--- a/openstack/common/rpc/impl_fake.py
+++ b/openstack/common/rpc/impl_fake.py
@@ -167,7 +167,7 @@ def cast(conf, context, topic, msg):
         pass
 
 
-def notify(conf, context, topic, msg):
+def notify(conf, context, topic, msg, envelope):
     check_serialize(msg)