1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py
index 4269a98db2..abe2c1971a 100644
--- a/synapse/federation/federation_base.py
+++ b/synapse/federation/federation_base.py
@@ -194,7 +194,7 @@ async def _check_sigs_on_pdu(
     # event id's domain (normally only the case for joins/leaves), and add additional
     # checks. Only do this if the room version has a concept of event ID domain
     # (ie, the room version uses old-style non-hash event IDs).
-    if room_version.event_format == EventFormatVersions.V1:
+    if room_version.event_format == EventFormatVersions.ROOM_V1_V2:
         event_domain = get_domain_from_id(pdu.event_id)
         if event_domain != sender_domain:
             try: