diff --git a/roomserver/version/version.go b/roomserver/version/version.go
index 729d00a8..1f66995d 100644
--- a/roomserver/version/version.go
+++ b/roomserver/version/version.go
@@ -23,7 +23,7 @@ import (
 // DefaultRoomVersion contains the room version that will, by
 // default, be used to create new rooms on this server.
 func DefaultRoomVersion() gomatrixserverlib.RoomVersion {
-	return gomatrixserverlib.RoomVersionV9
+	return gomatrixserverlib.RoomVersionV6
 }
 
 // RoomVersions returns a map of all known room versions to this