diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index fc36143..645cc30 100644
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Binary Increase Congestion control for TCP
  * Home page: