diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h
index 4994a43..36d6ce6 100644
--- a/include/linux/mailbox_controller.h
+++ b/include/linux/mailbox_controller.h
@@ -1,8 +1,4 @@
-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
 
 #ifndef __MAILBOX_CONTROLLER_H
 #define __MAILBOX_CONTROLLER_H