diff --git a/examples/host/cdc_msc_hid/src/tusb_config.h b/examples/host/cdc_msc_hid/src/tusb_config.h
index c515405cb..e3d9356f6 100644
--- a/examples/host/cdc_msc_hid/src/tusb_config.h
+++ b/examples/host/cdc_msc_hid/src/tusb_config.h
@@ -108,6 +108,10 @@
 #define CFG_TUH_HID_EPIN_BUFSIZE    64
 #define CFG_TUH_HID_EPOUT_BUFSIZE   64
 
+//------------- CDC -------------//
+// Set both DTR ( bit 0), RTS (bit 1) on enumeration/mounted
+#define CFG_TUH_CDC_SET_DTRRTS_ON_ENUM    0x03
+
 #ifdef __cplusplus
  }
 #endif
diff --git a/src/class/cdc/cdc_host.h b/src/class/cdc/cdc_host.h
index 02ae69111..5407c646d 100644
--- a/src/class/cdc/cdc_host.h
+++ b/src/class/cdc/cdc_host.h
@@ -49,7 +49,7 @@
 
 // RX Endpoint size
 #ifndef CFG_TUH_CDC_RX_EPSIZE
-#define CFG_TUH_CDC_RX_EPSIZE USBH_EPSIZE_BULK_MAX
+#define CFG_TUH_CDC_RX_EPSIZE  USBH_EPSIZE_BULK_MAX
 #endif
 
 // TX FIFO size
@@ -59,7 +59,7 @@
 
 // TX Endpoint size
 #ifndef CFG_TUH_CDC_TX_EPSIZE
-#define CFG_TUH_CDC_TX_EPSIZE USBH_EPSIZE_BULK_MAX
+#define CFG_TUH_CDC_TX_EPSIZE  USBH_EPSIZE_BULK_MAX
 #endif
 
 //--------------------------------------------------------------------+
@@ -145,7 +145,9 @@ static inline bool tuh_cdc_disconnect(uint8_t idx, tuh_xfer_cb_t complete_cb, ui
   return tuh_cdc_set_control_line_state(idx, 0x00, complete_cb, user_data);
 }
 
-//------------- Application Callback -------------//
+//--------------------------------------------------------------------+
+// CDC APPLICATION CALLBACKS
+//--------------------------------------------------------------------+
 
 // Invoked when a device with CDC interface is mounted
 // idx is index of cdc interface in the internal pool.
@@ -160,26 +162,6 @@ TU_ATTR_WEAK extern void tuh_cdc_rx_cb(uint8_t idx);
 // Invoked when a TX is complete and therefore space becomes available in TX buffer
 TU_ATTR_WEAK extern void tuh_cdc_tx_complete_cb(uint8_t idx);
 
-//--------------------------------------------------------------------+
-// CDC APPLICATION CALLBACKS
-//--------------------------------------------------------------------+
-
-/** \brief      Callback function that is invoked when an transferring event occurred
- * \param[in]		dev_addr	Address of device
- * \param[in]   event an value from \ref xfer_result_t
- * \param[in]   pipe_id value from \ref cdc_pipeid_t indicate the pipe
- * \param[in]   xferred_bytes Number of bytes transferred via USB bus
- * \note        event can be one of following
- *              - XFER_RESULT_SUCCESS : previously scheduled transfer completes successfully.
- *              - XFER_RESULT_FAILED   : previously scheduled transfer encountered a transaction error.
- *              - XFER_RESULT_STALLED : previously scheduled transfer is stalled by device.
- * \note
- */
-// void tuh_cdc_xfer_isr(uint8_t dev_addr, xfer_result_t event, cdc_pipeid_t pipe_id, uint32_t xferred_bytes);
-
-/// @} // group CDC_Serial_Host
-/// @}
-
 //--------------------------------------------------------------------+
 // Internal Class Driver API
 //--------------------------------------------------------------------+