diff --git a/weed/filesys/dir_link.go b/weed/filesys/dir_link.go
index f36918734..368ded442 100644
--- a/weed/filesys/dir_link.go
+++ b/weed/filesys/dir_link.go
@@ -32,7 +32,7 @@ func (dir *Dir) Link(ctx context.Context, req *fuse.LinkRequest, old fs.Node) (f
 	}
 
 	// update old file to hardlink mode
-	if oldFile.entry.HardLinkId == nil {
+	if len(oldFile.entry.HardLinkId) == 0 {
 		oldFile.entry.HardLinkId = util.RandomBytes(16)
 		oldFile.entry.HardLinkCounter = 1
 	}