diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 4f47f5b6ae..d09743ed1b 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -131,7 +131,7 @@ class RoomCreationHandler(BaseHandler):
             if event.type == RoomMemberEvent.TYPE:
                 yield room_member_handler.change_membership(
                     event,
-                    do_auth=False
+                    do_auth=True
                 )
             else:
                 yield self._on_new_room_event(