Index: uspace/lib/c/include/ipc/dev_iface.h
===================================================================
--- uspace/lib/c/include/ipc/dev_iface.h	(revision 609243f4f1d6e7562d9c9b79e38925b36e844ac0)
+++ uspace/lib/c/include/ipc/dev_iface.h	(revision b2a6dacfb814723103c3f11e4fe5f012392bb59a)
@@ -36,4 +36,8 @@
 typedef enum {
 	HW_RES_DEV_IFACE = 0,
+
+	/** Audio device mixer interface */
+	AUDIO_MIXER_IFACE,
+
 	/** Character device interface */
 	CHAR_DEV_IFACE,