diff --git a/sys/dev/sound/pcm/mixer.h b/sys/dev/sound/pcm/mixer.h
index 2c8dff753e36..f4be41f0a325 100644
--- a/sys/dev/sound/pcm/mixer.h
+++ b/sys/dev/sound/pcm/mixer.h
@@ -47,4 +47,4 @@ void *mix_getdevinfo(struct snd_mixer *m);
  */
 #define	MIXER_SIZE	(512 + sizeof(struct kobj))
 
-#define MIXER_DECLARE(name) DEFINE_CLASS(name, name ## _methods, MIXER_SIZE)
+#define MIXER_DECLARE(name) static DEFINE_CLASS(name, name ## _methods, MIXER_SIZE)