diff --git a/notifications/notificationevent.py b/notifications/notificationevent.py
index 87a736878..ecc6a40a5 100644
--- a/notifications/notificationevent.py
+++ b/notifications/notificationevent.py
@@ -70,7 +70,10 @@ class NotificationEvent(object):
   @classmethod
   def event_names(cls):
     for subc in cls.__subclasses__():
-      if subc.event_name() is not None:
+      if subc.event_name() is None:
+        for subsubc in subc.__subclasses__():
+          yield subsubc.event_name()
+      else:
         yield subc.event_name()
 
   @staticmethod