diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c
index f95943a..fe04e23 100644
--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
  *