diff --git a/synapse/events/__init__.py b/synapse/events/__init__.py
index bd3ffb59c..7103b937a 100644
--- a/synapse/events/__init__.py
+++ b/synapse/events/__init__.py
@@ -94,6 +94,7 @@ class EventBase(object):
     event_id = _event_dict_property("event_id")
     hashes = _event_dict_property("hashes")
     origin = _event_dict_property("origin")
+    origin_server_ts = _event_dict_property("origin_server_ts")
     prev_events = _event_dict_property("prev_events")
     prev_state = _event_dict_property("prev_state")
     room_id = _event_dict_property("room_id")
diff --git a/synapse/rest/room.py b/synapse/rest/room.py
index 22e1244e5..c526e9bc7 100644
--- a/synapse/rest/room.py
+++ b/synapse/rest/room.py
@@ -117,10 +117,10 @@ class RoomStateEventRestServlet(RestServlet):
                                   self.on_PUT_no_state_key)
 
     def on_GET_no_state_key(self, request, room_id, event_type):
-        return self.on_GET(request, room_id, event_type, None)
+        return self.on_GET(request, room_id, event_type, "")
 
     def on_PUT_no_state_key(self, request, room_id, event_type):
-        return self.on_PUT(request, room_id, event_type, None)
+        return self.on_PUT(request, room_id, event_type, "")
 
     @defer.inlineCallbacks
     def on_GET(self, request, room_id, event_type, state_key):