diff --git a/lib_xua/api/xua_midi.h b/lib_xua/api/xua_midi.h
index 81a03eed..d7697fbb 100644
--- a/lib_xua/api/xua_midi.h
+++ b/lib_xua/api/xua_midi.h
@@ -58,23 +58,26 @@ INLINE void midi_get_ack_or_data(chanend c, int &is_ack, unsigned int &datum) {
   if (testct(c)) {
     is_ack = 1;
     (void) inct(c); // read 1-bytes control token
-    (void) inuchar(c);
-    (void) inuchar(c);
-    (void) inuchar(c);
+    chkct(c, XS1_CT_END);
   }
   else {
     is_ack = 0;
     datum = inuint(c);
+    chkct(c, XS1_CT_END);
   }
 }
 #endif
 
 INLINE void midi_send_ack(chanend c) {
   outct(c, MIDI_ACK);
-  outuchar(c, 0);
-  outuchar(c, 0);
-  outuchar(c, 0);
+  outct(c, XS1_CT_END);
 }
+
+INLINE void midi_send_data(chanend c, unsigned int datum) {
+  outuint(c, datum);
+  outct(c, XS1_CT_END);
+}
+
 #define MIDI_RATE           (31250)
 #define MIDI_BITTIME        (XS1_TIMER_MHZ * 1000000 / MIDI_RATE)
 #define MIDI_BITTIME_2      (MIDI_BITTIME>>1)
diff --git a/lib_xua/src/core/buffer/ep/ep_buffer.xc b/lib_xua/src/core/buffer/ep/ep_buffer.xc
index b2d2cbb1..537210a0 100644
--- a/lib_xua/src/core/buffer/ep/ep_buffer.xc
+++ b/lib_xua/src/core/buffer/ep/ep_buffer.xc
@@ -839,7 +839,7 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
                     if (midi_data_remaining_to_device)
                     {
                         read_via_xc_ptr(datum, midi_from_host_rdptr);
-                        outuint(c_midi, datum);
+                        midi_send_data(c_midi, datum);
                         midi_from_host_rdptr += 4;
                         midi_data_remaining_to_device -= 4;
                     }
@@ -992,8 +992,7 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
                     {
                         /* Read another word from the fifo and output it to MIDI thread */
                         read_via_xc_ptr(datum, midi_from_host_rdptr);
-                        outuint(c_midi, datum);
-                        outct(c_midi, XS1_CT_PAUSE);
+                        midi_send_data(c_midi, datum);
                         midi_from_host_rdptr += 4;
                         midi_data_remaining_to_device -= 4;
                     }
@@ -1002,7 +1001,6 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
                 {
                     /* The midi/uart thread has sent us some data - handshake back */
                     midi_send_ack(c_midi);
-                    outct(c_midi, XS1_CT_PAUSE);
                     if (midi_data_collected_from_device < MIDI_USB_BUFFER_TO_HOST_SIZE)
                     {
                         /* There is room in the collecting buffer for the data */
diff --git a/lib_xua/src/midi/usb_midi.xc b/lib_xua/src/midi/usb_midi.xc
index a81b235f..34c9c6f4 100644
--- a/lib_xua/src/midi/usb_midi.xc
+++ b/lib_xua/src/midi/usb_midi.xc
@@ -197,7 +197,7 @@ void usb_midi(
                                 {
                                     // send data
                                     // printstr("uart->decouple: ");
-                                    outuint(c_midi, event);
+                                    midi_send_data(c_midi, event);
                                     waiting_for_ack = 1;
                                     th_count++;
                                 }
@@ -272,7 +272,7 @@ void usb_midi(
                 // have we got more data to send
                 if (!queue_is_empty(midi_to_host_fifo))
                 {
-                    outuint(c_midi, queue_pop_word(midi_to_host_fifo, midi_to_host_fifo_arr));
+                    midi_send_data(c_midi, queue_pop_word(midi_to_host_fifo, midi_to_host_fifo_arr));
                     th_count++;
                 }
                 else
@@ -296,7 +296,7 @@ void usb_midi(
                     {
                         // send data
                         event = byterev(event);
-                        outuint(c_midi, event);
+                        midi_send_data(c_midi, event);
                         th_count++;
                         waiting_for_ack = 1;
                     }