diff --git a/weed/util/http_util.go b/weed/util/http_util.go
index 92681d8e8..00dac26f7 100644
--- a/weed/util/http_util.go
+++ b/weed/util/http_util.go
@@ -331,7 +331,9 @@ func ReadUrlAsStream(fileUrl string, cipherKey []byte, isContentGzipped bool, is
 
 	for {
 		m, err = reader.Read(buf)
-		fn(buf[:m])
+		if m > 0 {
+			fn(buf[:m])
+		}
 		if err == io.EOF {
 			return false, nil
 		}