1 files changed, 3 insertions, 5 deletions
diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py
index d32d224d56..eedde97ab0 100644
--- a/synapse/handlers/federation_event.py
+++ b/synapse/handlers/federation_event.py
@@ -723,12 +723,11 @@ class FederationEventHandler:
         if not prevs - seen:
             return
 
-        latest_list = await self._store.get_latest_event_ids_in_room(room_id)
+        latest_frozen = await self._store.get_latest_event_ids_in_room(room_id)
 
         # We add the prev events that we have seen to the latest
         # list to ensure the remote server doesn't give them to us
-        latest = set(latest_list)
-        latest |= seen
+        latest = seen | latest_frozen
 
         logger.info(
             "Requesting missing events between %s and %s",
@@ -1976,8 +1975,7 @@ class FederationEventHandler:
             # partial and full state and may not be accurate.
             return
 
-        extrem_ids_list = await self._store.get_latest_event_ids_in_room(event.room_id)
-        extrem_ids = set(extrem_ids_list)
+        extrem_ids = await self._store.get_latest_event_ids_in_room(event.room_id)
         prev_event_ids = set(event.prev_event_ids())
 
         if extrem_ids == prev_event_ids: