diff --git a/metropolis/pkg/event/etcd/etcd.go b/metropolis/pkg/event/etcd/etcd.go
index 14dfd99..71e8056 100644
--- a/metropolis/pkg/event/etcd/etcd.go
+++ b/metropolis/pkg/event/etcd/etcd.go
@@ -402,7 +402,7 @@
 	}
 
 	if backlogOnly && len(w.backlogged) == 0 {
-		return empty, event.BacklogDone
+		return empty, event.ErrBacklogDone
 	}
 
 	// Update backlog from etcd if needed.