diff --git a/arch/x86/include/asm/apm.h b/arch/x86/include/asm/apm.h
index 93eebc63..4d4015d 100644
--- a/arch/x86/include/asm/apm.h
+++ b/arch/x86/include/asm/apm.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  *  Machine specific APM BIOS functions for generic.
  *  Split out from apm.c by Osamu Tomita <tomita@cinet.co.jp>