diff --git a/src/main.c b/src/main.c
index 549d16c..5d5fb2b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -96,47 +96,6 @@ _write (const char *s, int size)
 
 extern void *USBthread (void *arg);
 
-extern void EP1_IN_Callback (void);
-extern void EP2_IN_Callback (void);
-extern void EP1_OUT_Callback (void);
-extern void EP6_IN_Callback (void);
-
-void
-usb_cb_rx_ready (uint8_t ep_num)
-{
-  if (ep_num == ENDP1)
-    EP1_OUT_Callback ();
-#ifdef DEBUG
-  else if (ep_num == ENDP5)
-    {
-      chopstx_mutex_lock (&stdout.m_dev);
-      usb_lld_rx_enable (ep_num);
-      chopstx_mutex_unlock (&stdout.m_dev);
-    }
-#endif
-}
-
-void
-usb_cb_tx_done (uint8_t ep_num)
-{
-  if (ep_num == ENDP1)
-    EP1_IN_Callback ();
-  else if (ep_num == ENDP2)
-    EP2_IN_Callback ();
-#ifdef DEBUG
-  else if (ep_num == ENDP3)
-    {
-      chopstx_mutex_lock (&stdout.m_dev);
-      chopstx_cond_signal (&stdout.cond_dev);
-      chopstx_mutex_unlock (&stdout.m_dev);
-    }
-#endif
-#ifdef PINPAD_SUPPORT
-  else if (ep_num == ENDP6)
-    EP6_IN_Callback ();
-#endif
-}
-
 
 /*
  * main thread does 1-bit LED display output
diff --git a/src/usb_ctrl.c b/src/usb_ctrl.c
index d28c8fb..f032b7e 100644
--- a/src/usb_ctrl.c
+++ b/src/usb_ctrl.c
@@ -512,3 +512,44 @@ usb_intr (void *arg)
 
   return NULL;
 }
+
+extern void EP1_IN_Callback (void);
+extern void EP2_IN_Callback (void);
+extern void EP1_OUT_Callback (void);
+extern void EP6_IN_Callback (void);
+
+void
+usb_cb_rx_ready (uint8_t ep_num)
+{
+  if (ep_num == ENDP1)
+    EP1_OUT_Callback ();
+#ifdef DEBUG
+  else if (ep_num == ENDP5)
+    {
+      chopstx_mutex_lock (&stdout.m_dev);
+      usb_lld_rx_enable (ep_num);
+      chopstx_mutex_unlock (&stdout.m_dev);
+    }
+#endif
+}
+
+void
+usb_cb_tx_done (uint8_t ep_num)
+{
+  if (ep_num == ENDP1)
+    EP1_IN_Callback ();
+  else if (ep_num == ENDP2)
+    EP2_IN_Callback ();
+#ifdef DEBUG
+  else if (ep_num == ENDP3)
+    {
+      chopstx_mutex_lock (&stdout.m_dev);
+      chopstx_cond_signal (&stdout.cond_dev);
+      chopstx_mutex_unlock (&stdout.m_dev);
+    }
+#endif
+#ifdef PINPAD_SUPPORT
+  else if (ep_num == ENDP6)
+    EP6_IN_Callback ();
+#endif
+}