diff --git a/libj1939.h b/libj1939.h
index 64d28b1..500a922 100644
--- a/libj1939.h
+++ b/libj1939.h
@@ -1,3 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2011 EIA Electronics
+ *
+ * Authors:
+ * Kurt Van Dijck <kurt.van.dijck@eia.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the version 2 of the GNU General Public License
+ * as published by the Free Software Foundation
+ */
+
 #include <sys/socket.h>
 #include <linux/can.h>
 #include <linux/can/j1939.h>