diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h
index 822c135..120225e 100644
--- a/include/linux/debug_locks.h
+++ b/include/linux/debug_locks.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __LINUX_DEBUG_LOCKING_H
 #define __LINUX_DEBUG_LOCKING_H