diff --git a/synapse/storage/databases/main/relations.py b/synapse/storage/databases/main/relations.py
index c54134eb1e64..2275a583508b 100644
--- a/synapse/storage/databases/main/relations.py
+++ b/synapse/storage/databases/main/relations.py
@@ -859,7 +859,7 @@ async def get_threads(
                 relation_type = '{RelationTypes.THREAD}'
                 {pagination_clause}
             GROUP BY relates_to_id
-            ORDER BY topological_ordering DESC, stream_ordering DESC
+            ORDER BY MAX(topological_ordering) DESC, MAX(stream_ordering) DESC
             LIMIT ?
         """