diff --git a/library/GTP_Emulation.ttcn b/library/GTP_Emulation.ttcn
index 4368a8a..43c034b 100644
--- a/library/GTP_Emulation.ttcn
+++ b/library/GTP_Emulation.ttcn
@@ -1,3 +1,14 @@
+/* GTP Emulation in TTCN-3
+ *
+ * (C) 2018 Harald Welte <laforge@gnumonks.org>
+ * All rights reserved.
+ *
+ * Released under the terms of GNU General Public License, Version 2 or
+ * (at your option) any later version.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
 module GTP_Emulation {
 
 import from IPL4asp_Types all;