diff --git a/arch/x86/Kbuild b/arch/x86/Kbuild
index c625f57..30dec01 100644
--- a/arch/x86/Kbuild
+++ b/arch/x86/Kbuild
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 obj-y += entry/
 
 obj-$(CONFIG_PERF_EVENTS) += events/