diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
index 2c7b9c9c2aa642eea27f6d533c348e0043986b62..7423f998cfb5bfc2f74ea2c592b8b300bc08f176 100644
--- a/sound/usb/mixer.h
+++ b/sound/usb/mixer.h
@@ -53,6 +53,7 @@ struct usb_mixer_elem_info {
 	int cached;
 	int cache_val[MAX_CHANNELS];
 	u8 initialized;
+	void *private_data;
 };
 
 int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,