diff --git a/include/net/datalink.h b/include/net/datalink.h
index 93cb18f..a966322 100644
--- a/include/net/datalink.h
+++ b/include/net/datalink.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _NET_INET_DATALINK_H_
 #define _NET_INET_DATALINK_H_