diff --git a/shared/tinyusb/mp_cdc_common.c b/shared/tinyusb/mp_cdc_common.c
index cd4f5d1013..4ccae4bac1 100644
--- a/shared/tinyusb/mp_cdc_common.c
+++ b/shared/tinyusb/mp_cdc_common.c
@@ -39,7 +39,13 @@ STATIC void usbd_cdc_run_bootloader_task(mp_sched_node_t *node) {
     machine_bootloader(0, NULL);
 }
 
-void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts) {
+void
+#if MICROPY_HW_USB_EXTERNAL_TINYUSB
+mp_usbd_line_state_cb
+#else
+tud_cdc_line_state_cb
+#endif
+    (uint8_t itf, bool dtr, bool rts) {
     if (dtr == false && rts == false) {
         // Device is disconnected.
         cdc_line_coding_t line_coding;