diff --git a/src/gsm/milenage/aes.h b/src/gsm/milenage/aes.h
index ce42b20..5410c36 100644
--- a/src/gsm/milenage/aes.h
+++ b/src/gsm/milenage/aes.h
@@ -10,6 +10,8 @@
  * Alternatively, this software may be distributed under the terms of BSD
  * license.
  *
+ * SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+ *
  * See README and COPYING for more details.
  */