1 files changed, 3 insertions, 3 deletions
diff --git a/synapse/rest/client/sync.py b/synapse/rest/client/sync.py
index b6a2485732..88e4f5e063 100644
--- a/synapse/rest/client/sync.py
+++ b/synapse/rest/client/sync.py
@@ -520,9 +520,9 @@ class SyncRestServlet(RestServlet):
             return self._event_serializer.serialize_events(
                 events,
                 time_now=time_now,
-                # We don't bundle "live" events, as otherwise clients
-                # will end up double counting annotations.
-                bundle_relations=False,
+                # Don't bother to bundle aggregations if the timeline is unlimited,
+                # as clients will have all the necessary information.
+                bundle_aggregations=room.timeline.limited,
                 token_id=token_id,
                 event_format=event_formatter,
                 only_event_fields=only_fields,