1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/rest/client/events.py b/synapse/rest/client/events.py
index 3eca4fe21f..5705f812a5 100644
--- a/synapse/rest/client/events.py
+++ b/synapse/rest/client/events.py
@@ -93,7 +93,7 @@ class EventRestServlet(RestServlet):
         event = await self.event_handler.get_event(requester.user, None, event_id)
 
         if event:
-            result = self._event_serializer.serialize_event(
+            result = await self._event_serializer.serialize_event(
                 event,
                 self.clock.time_msec(),
                 config=SerializeEventConfig(requester=requester),