diff --git a/module_usb_aud_shared/endpoint0/descriptors_2.h b/module_usb_aud_shared/endpoint0/descriptors_2.h
index 32d03f00..5dc15a9a 100644
--- a/module_usb_aud_shared/endpoint0/descriptors_2.h
+++ b/module_usb_aud_shared/endpoint0/descriptors_2.h
@@ -1236,6 +1236,33 @@ unsigned char cfgDesc_Audio2[] =
 #define APPEND_VENDOR_STR(x) VENDOR_STR#x
 
 /* String table */
+#ifdef SPDIF_RX
+#define SPDIF_RX_NUM_STRS   1
+#else
+#define SPDIF_TX_NUM_STRS   0
+#endif
+
+#ifdef ADAT_RX
+#define ADAT_RX_NUM_STRS    1
+#else
+#define ADAT_RX_NUM_STRS    0
+#endif
+
+#ifdef MIDI
+#define MIDI_NUM_STRS       2
+#else
+#define MIDI_NUM_STRS       0
+#endif
+
+#ifdef DFU
+#define DFU_NUM_STRS       1
+#else
+#define DFU_NUM_STRS       0
+#endif
+
+
+#define STR_INDEX_OUT_CHAN  (10 + SPDIF_RX_NUM_STRS + ADAT_RX_NUM_STRS + MIDI_NUM_STRS + DFU_NUM_STRS)
+#define STR_INDEX_IN_CHAN   (STR_INDEX_OUT_CHAN + NUM_USB_CHAN_OUT)
 
 static unsigned char strDescs_Audio2[][40] = 
 {