diff --git a/src/music/null_m.h b/src/music/null_m.h
--- a/src/music/null_m.h
+++ b/src/music/null_m.h
@@ -7,4 +7,4 @@
 
 extern const HalMusicDriver _null_music_driver;
 
-#endif
+#endif /* MUSIC_NULL_H */