diff --git a/fs/dir.go b/fs/dir.go
index 891dc8d63..c90c1222f 100644
--- a/fs/dir.go
+++ b/fs/dir.go
@@ -28,6 +28,7 @@ func NewDirCopy(d Directory) *Dir {
 		modTime: d.ModTime(),
 		size:    d.Size(),
 		items:   d.Items(),
+		id:      d.ID(),
 	}
 }