diff --git a/ryu/controller/handler.py b/ryu/controller/handler.py
index 615fd120..ba45b0dc 100644
--- a/ryu/controller/handler.py
+++ b/ryu/controller/handler.py
@@ -38,7 +38,7 @@ def set_ev_cls(ev_cls, dispatchers=None):
     return _set_ev_cls_dec
 
 
-def set_ev_handler(ev_cls, dispatchers):
+def set_ev_handler(ev_cls, dispatchers=None):
     def _set_ev_cls_dec(handler):
         handler.ev_cls = ev_cls
         handler.dispatchers = _listify(dispatchers)