diff --git a/include/tinycrypt/ecc_dh.h b/include/tinycrypt/ecc_dh.h
index c680a77..ac4ff14 100644
--- a/include/tinycrypt/ecc_dh.h
+++ b/include/tinycrypt/ecc_dh.h
@@ -4,6 +4,8 @@
  * Copyright (c) 2014, Kenneth MacKay
  * All rights reserved.
  *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *