diff --git a/collect.go b/collect.go
index 0f1c1bb..5b35971 100644
--- a/collect.go
+++ b/collect.go
@@ -52,7 +52,7 @@ func collectCopyCountLiveAnchors(cxt *WorkerContext) {
 				}
 				c := &CountLiveAnchors{}
 
-				c.UID = la.ObjectID.String()
+				c.UID = la.ObjectID.Hex()
 				c.IsCounted = 0
 				c.CreateAt = la.CreateAt