diff --git a/kernel/.gitignore b/kernel/.gitignore
index 0a423a3..78701ea 100644
--- a/kernel/.gitignore
+++ b/kernel/.gitignore
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 kheaders.md5
 timeconst.h
 hz.bc