Index: uspace/lib/c/include/ipc/dev_iface.h
===================================================================
--- uspace/lib/c/include/ipc/dev_iface.h	(revision 9991c47fc8c46d0e24bc1c32ff3c50cc3e8b340d)
+++ uspace/lib/c/include/ipc/dev_iface.h	(revision 9d1488d01b27c1533499e7bc91d01690b08a7db6)
@@ -36,4 +36,8 @@
 typedef enum {
 	HW_RES_DEV_IFACE = 0,
+
+	/** Audio device mixer interface */
+	AUDIO_MIXER_IFACE,
+
 	/** Character device interface */
 	CHAR_DEV_IFACE,