diff --git a/ports/teensy/teensy_hal.c b/ports/teensy/teensy_hal.c
index 84d68cff89..7ce82f1d2a 100644
--- a/ports/teensy/teensy_hal.c
+++ b/ports/teensy/teensy_hal.c
@@ -49,6 +49,7 @@ void mp_hal_stdout_tx_strn(const char *str, size_t len) {
 void mp_hal_stdout_tx_strn_cooked(const char *str, size_t len) {
     // send stdout to UART and USB CDC VCP
     if (MP_STATE_PORT(pyb_stdio_uart) != NULL) {
+        void uart_tx_strn_cooked(pyb_uart_obj_t *uart_obj, const char *str, uint len);
         uart_tx_strn_cooked(MP_STATE_PORT(pyb_stdio_uart), str, len);
     }
     if (usb_vcp_is_enabled()) {
diff --git a/ports/teensy/uart.c b/ports/teensy/uart.c
index 3d5111217b..a8cfd63eac 100644
--- a/ports/teensy/uart.c
+++ b/ports/teensy/uart.c
@@ -426,11 +426,13 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_uart_send_obj, 1, pyb_uart_send);
 ///
 /// Return value: if `recv` is an integer then a new buffer of the bytes received,
 /// otherwise the same buffer that was passed in to `recv`.
+#if 0
 STATIC const mp_arg_t pyb_uart_recv_args[] = {
     { MP_QSTR_recv,    MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
     { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 5000} },
 };
 #define PYB_UART_RECV_NUM_ARGS MP_ARRAY_SIZE(pyb_uart_recv_args)
+#endif
 
 STATIC mp_obj_t pyb_uart_recv(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
     // TODO assumes transmission size is 8-bits wide