diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 09f64e01..97359bb5 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -7,6 +7,8 @@ UNRELEASED
   * FIXED:     Device fails to enumerate when ADAT and S/PDIF transmit are enabled
   * CHANGED:   Enable only the minimum number of ADAT input formats based for the
     supported sample frequencies
+  * FIXED:     Incorrect internal input EP count for input only devices
+  * ADDED:     MIDI unit and subsystem tests
   * FIXED:     ADAT Tx called too frequently
 
 4.0.0
diff --git a/lib_xua/api/xua_conf_default.h b/lib_xua/api/xua_conf_default.h
index 053dff28..82be6dab 100644
--- a/lib_xua/api/xua_conf_default.h
+++ b/lib_xua/api/xua_conf_default.h
@@ -1273,7 +1273,9 @@ enum USBEndpointNumber_In
 #if (NUM_USB_CHAN_IN == 0) || defined (UAC_FORCE_FEEDBACK_EP)
     ENDPOINT_NUMBER_IN_FEEDBACK,
 #endif
+#if (NUM_USB_CHAN_IN != 0)
     ENDPOINT_NUMBER_IN_AUDIO,
+#endif
 #if (XUA_SPDIF_RX_EN) || (XUA_ADAT_RX_EN)
     ENDPOINT_NUMBER_IN_INTERRUPT,   /* Audio interrupt/status EP */
 #endif
diff --git a/lib_xua/src/core/endpoint0/xua_endpoint0.c b/lib_xua/src/core/endpoint0/xua_endpoint0.c
index c24dfefc..6a656f95 100755
--- a/lib_xua/src/core/endpoint0/xua_endpoint0.c
+++ b/lib_xua/src/core/endpoint0/xua_endpoint0.c
@@ -1,4 +1,4 @@
-// Copyright 2011-2023 XMOS LIMITED.
+// Copyright 2011-2024 XMOS LIMITED.
 // This Software is subject to the terms of the XMOS Public Licence: Version 1.
 /**
  * @brief   Implements endpoint zero for an USB Audio 1.0/2.0 device
@@ -814,7 +814,14 @@ void XUA_Endpoint0_loop(XUD_Result_t result, USB_SetupPacket_t sp, chanend c_ep0
                 {
                     unsigned epNum = sp.wIndex & 0xff;
 
-                    if ((epNum == ENDPOINT_ADDRESS_OUT_AUDIO) || (epNum == ENDPOINT_ADDRESS_IN_AUDIO))
+// Ensure we only check for AUDIO EPs if enabled
+#if (NUM_USB_CHAN_IN != 0 && NUM_USB_CHAN_OUT == 0)
+                    if (epNum == ENDPOINT_ADDRESS_IN_AUDIO)
+#elif (NUM_USB_CHAN_IN == 0 && NUM_USB_CHAN_OUT != 0)
+                    if (epNum == ENDPOINT_ADDRESS_OUT_AUDIO)
+#elif (NUM_USB_CHAN_IN != 0 && NUM_USB_CHAN_OUT != 0)
+                    if ((epNum == ENDPOINT_ADDRESS_IN_AUDIO) || (epNum == ENDPOINT_ADDRESS_OUT_AUDIO))
+#endif
                     {
 #if (AUDIO_CLASS == 2) && (AUDIO_CLASS_FALLBACK)
                         if(g_curUsbSpeed == XUD_SPEED_FS)