diff --git a/ports/esp32/boards/ARDUINO_NANO_ESP32/board_init.c b/ports/esp32/boards/ARDUINO_NANO_ESP32/board_init.c
index ab03139d9..69a414cd5 100644
--- a/ports/esp32/boards/ARDUINO_NANO_ESP32/board_init.c
+++ b/ports/esp32/boards/ARDUINO_NANO_ESP32/board_init.c
@@ -26,6 +26,7 @@
 
 #include <string.h>
 #include "py/mphal.h"
+#include "shared/tinyusb/mp_usbd_cdc.h"
 
 #include <esp_system.h>
 #include <esp_ota_ops.h>
@@ -87,7 +88,6 @@ void NANO_ESP32_enter_bootloader(void) {
 }
 
 void NANO_ESP32_usb_callback_line_state_changed(int itf, void *event_in) {
-    extern void mp_usbd_line_state_cb(uint8_t itf, bool dtr, bool rts);
     cdcacm_event_t *event = event_in;
     mp_usbd_line_state_cb(itf, event->line_state_changed_data.dtr, event->line_state_changed_data.rts);
 }
diff --git a/ports/esp32/usb.c b/ports/esp32/usb.c
index 316482e18..2a3a2595d 100644
--- a/ports/esp32/usb.c
+++ b/ports/esp32/usb.c
@@ -79,7 +79,7 @@ void usb_init(void) {
         .callback_rx_wanted_char = &MICROPY_HW_USB_CUSTOM_RX_WANTED_CHAR_CB,
         #endif
         #ifdef MICROPY_HW_USB_CUSTOM_LINE_STATE_CB
-        .callback_line_state_changed = &MICROPY_HW_USB_CUSTOM_LINE_STATE_CB,
+        .callback_line_state_changed = (tusb_cdcacm_callback_t)&MICROPY_HW_USB_CUSTOM_LINE_STATE_CB,
         #endif
         #ifdef MICROPY_HW_USB_CUSTOM_LINE_CODING_CB
         .callback_line_coding_changed = &MICROPY_HW_USB_CUSTOM_LINE_CODING_CB,
diff --git a/ports/nrf/mpconfigport.h b/ports/nrf/mpconfigport.h
index 6e92fa876..0b9b667ee 100644
--- a/ports/nrf/mpconfigport.h
+++ b/ports/nrf/mpconfigport.h
@@ -335,6 +335,7 @@ long unsigned int rng_generate_random_word(void);
 #if MICROPY_HW_USB_CDC
 #include "device/usbd.h"
 #define MICROPY_HW_USBDEV_TASK_HOOK extern void tud_task(void); tud_task();
+#define MICROPY_EXCLUDE_SHARED_TINYUSB_USBD_CDC (1)
 #else
 #define MICROPY_HW_USBDEV_TASK_HOOK ;
 #endif
diff --git a/shared/tinyusb/mp_usbd_cdc.c b/shared/tinyusb/mp_usbd_cdc.c
index 4135cd720..6d789ff5e 100644
--- a/shared/tinyusb/mp_usbd_cdc.c
+++ b/shared/tinyusb/mp_usbd_cdc.c
@@ -26,16 +26,13 @@
 
 #include "py/runtime.h"
 #include "py/mphal.h"
-#include "py/mpconfig.h"
 #include "py/stream.h"
 #include "extmod/modmachine.h"
 
-#if MICROPY_HW_USB_CDC && MICROPY_HW_ENABLE_USBDEV
-#include "tusb.h"
-#include "device/usbd.h"
-
-#include "mp_usbd_cdc.h"
 #include "mp_usbd.h"
+#include "mp_usbd_cdc.h"
+
+#if MICROPY_HW_USB_CDC && MICROPY_HW_ENABLE_USBDEV && !MICROPY_EXCLUDE_SHARED_TINYUSB_USBD_CDC
 
 static uint8_t cdc_itf_pending; // keep track of cdc interfaces which need attention to poll
 
@@ -122,6 +119,8 @@ mp_uint_t mp_usbd_cdc_tx_strn(const char *str, mp_uint_t len) {
     return i;
 }
 
+#endif
+
 #if MICROPY_HW_USB_CDC_1200BPS_TOUCH && MICROPY_HW_ENABLE_USBDEV
 
 static mp_sched_node_t mp_bootloader_sched_node;
@@ -150,4 +149,3 @@ tud_cdc_line_state_cb
 }
 
 #endif
-#endif
diff --git a/shared/tinyusb/mp_usbd_cdc.h b/shared/tinyusb/mp_usbd_cdc.h
index f84cf8d03..1abe0fa0a 100644
--- a/shared/tinyusb/mp_usbd_cdc.h
+++ b/shared/tinyusb/mp_usbd_cdc.h
@@ -35,5 +35,8 @@ uintptr_t mp_usbd_cdc_poll_interfaces(uintptr_t poll_flags);
 void tud_cdc_rx_cb(uint8_t itf);
 mp_uint_t mp_usbd_cdc_tx_strn(const char *str, mp_uint_t len);
 
+#if MICROPY_HW_USB_EXTERNAL_TINYUSB
+void mp_usbd_line_state_cb(uint8_t itf, bool dtr, bool rts);
+#endif
 
 #endif // MICROPY_INCLUDED_SHARED_TINYUSB_MP_USBD_CDC_H