1 files changed, 2 insertions, 4 deletions
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index 1c9456e583..0c20601600 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -402,11 +402,9 @@ class UnsupportedRoomVersionError(SynapseError):
     """The client's request to create a room used a room version that the server does
     not support."""
 
-    def __init__(self):
+    def __init__(self, msg="Homeserver does not support this room version"):
         super(UnsupportedRoomVersionError, self).__init__(
-            code=400,
-            msg="Homeserver does not support this room version",
-            errcode=Codes.UNSUPPORTED_ROOM_VERSION,
+            code=400, msg=msg, errcode=Codes.UNSUPPORTED_ROOM_VERSION,
         )