diff --git a/audio/audio.h b/audio/audio.h
index 5579afd..9abd593 100644
--- a/audio/audio.h
+++ b/audio/audio.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier:BSD-3-Clause */
 #ifndef AUDIO_H
 #define AUDIO_H