diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index cae4612..5bd3f15 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __LINUX_PREEMPT_H
 #define __LINUX_PREEMPT_H