diff --git a/lib/os/os_test.go b/lib/os/os_test.go
index aa5337a2..7ff57ad3 100644
--- a/lib/os/os_test.go
+++ b/lib/os/os_test.go
@@ -1,3 +1,7 @@
+// Copyright 2022, Shulhan <ms@kilabit.info>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 package os
 
 import (