diff --git a/mm/Makefile b/mm/Makefile
index e3ac3ae..4659b93 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the linux memory manager.
 #