diff --git a/src/github.com/matrix-org/dendrite/roomserver/input/membership.go b/src/github.com/matrix-org/dendrite/roomserver/input/membership.go
index 1b4fac5ed..0c3fbb80a 100644
--- a/src/github.com/matrix-org/dendrite/roomserver/input/membership.go
+++ b/src/github.com/matrix-org/dendrite/roomserver/input/membership.go
@@ -81,7 +81,7 @@ func updateMemberships(
 			return nil, err
 		}
 	}
-	return nil, nil
+	return updates, nil
 }
 
 func updateMembership(