diff --git a/src/crc16.c b/src/crc16.c
index c03c008..29dace2 100644
--- a/src/crc16.c
+++ b/src/crc16.c
@@ -8,6 +8,8 @@
  *
  * This source code is licensed under the GNU General Public License,
  * Version 2. See the file COPYING for more details.
+ *
+ * SPDX-License-Identifier: GPL-2.0
  */
 
 #include <osmocom/core/crc16.h>