diff --git a/ryu/controller/ofp_event.py b/ryu/controller/ofp_event.py
index 2175e50a..43e7113b 100644
--- a/ryu/controller/ofp_event.py
+++ b/ryu/controller/ofp_event.py
@@ -40,8 +40,12 @@ def _ofp_msg_name_to_ev_name(msg_name):
 
 
 def ofp_msg_to_ev(msg):
-    name = _ofp_msg_name_to_ev_name(msg.__class__.__name__)
-    return _OFP_MSG_EVENTS[name](msg)
+    return ofp_msg_to_ev_cls(msg.__class__)(msg)
+
+
+def ofp_msg_to_ev_cls(msg_cls):
+    name = _ofp_msg_name_to_ev_name(msg_cls.__name__)
+    return _OFP_MSG_EVENTS[name]
 
 
 def _create_ofp_msg_ev_class(msg_cls):