diff --git a/syncapi/routing/memberships.go b/syncapi/routing/memberships.go
index 05c7deef0..3fcc3235c 100644
--- a/syncapi/routing/memberships.go
+++ b/syncapi/routing/memberships.go
@@ -135,6 +135,6 @@ func GetMemberships(
 	}
 	return util.JSONResponse{
 		Code: http.StatusOK,
-		JSON: getMembershipResponse{gomatrixserverlib.HeaderedToClientEvents(result, gomatrixserverlib.FormatSync)},
+		JSON: getMembershipResponse{gomatrixserverlib.HeaderedToClientEvents(result, gomatrixserverlib.FormatAll)},
 	}
 }