diff --git a/src/platform.c b/src/platform.c
index 8619772..a24cd30 100644
--- a/src/platform.c
+++ b/src/platform.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
 #include "msgbuf/platform.h"
 #include "base.h"
 #include "msgbuf.h"