diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index 12c6922..f7456c4 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the Linux proc filesystem routines.
 #