diff --git a/ports/esp8266/machine_uart.c b/ports/esp8266/machine_uart.c
index 4e88eee162..2fe6516dc7 100644
--- a/ports/esp8266/machine_uart.c
+++ b/ports/esp8266/machine_uart.c
@@ -231,10 +231,20 @@ STATIC mp_obj_t pyb_uart_any(mp_obj_t self_in) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_uart_any_obj, pyb_uart_any);
 
+STATIC mp_obj_t machine_uart_txdone(mp_obj_t self_in) {
+    pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
+
+    return uart_txdone(self->uart_id) == true ? mp_const_true : mp_const_false;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_uart_txdone_obj, machine_uart_txdone);
+
 STATIC const mp_rom_map_elem_t pyb_uart_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&pyb_uart_init_obj) },
 
     { MP_ROM_QSTR(MP_QSTR_any), MP_ROM_PTR(&pyb_uart_any_obj) },
+    { MP_ROM_QSTR(MP_QSTR_txdone), MP_ROM_PTR(&machine_uart_txdone_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR_flush), MP_ROM_PTR(&mp_stream_flush_obj) },
     { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
     { MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
     { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
@@ -305,6 +315,20 @@ STATIC mp_uint_t pyb_uart_ioctl(mp_obj_t self_in, mp_uint_t request, mp_uint_t a
         if ((flags & MP_STREAM_POLL_WR) && uart_tx_any_room(self->uart_id)) {
             ret |= MP_STREAM_POLL_WR;
         }
+    } else if (request == MP_STREAM_FLUSH) {
+        // The timeout is estimated using the buffer size and the baudrate.
+        // Take the worst case assumptions at 13 bit symbol size times 2.
+        uint64_t timeout = (uint64_t)(3 + 127) * 13000000ll * 2 / self->baudrate
+            + system_get_time();
+        do {
+            if (machine_uart_txdone((mp_obj_t)self) == mp_const_true) {
+                return 0;
+            }
+            MICROPY_EVENT_POLL_HOOK
+        } while (system_get_time() < timeout);
+
+        *errcode = MP_ETIMEDOUT;
+        ret = MP_STREAM_ERROR;
     } else {
         *errcode = MP_EINVAL;
         ret = MP_STREAM_ERROR;
diff --git a/ports/esp8266/uart.c b/ports/esp8266/uart.c
index 978a7efc38..117cd1bf6c 100644
--- a/ports/esp8266/uart.c
+++ b/ports/esp8266/uart.c
@@ -111,6 +111,15 @@ void uart_tx_one_char(uint8 uart, uint8 TxChar) {
     WRITE_PERI_REG(UART_FIFO(uart), TxChar);
 }
 
+int uart_txdone(uint8 uart) {
+    uint32 fifo_cnt = READ_PERI_REG(UART_STATUS(uart)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S);
+    if ((fifo_cnt >> UART_TXFIFO_CNT_S & UART_TXFIFO_CNT) == 0) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
 void uart_flush(uint8 uart) {
     while (true) {
         uint32 fifo_cnt = READ_PERI_REG(UART_STATUS(uart)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S);
diff --git a/ports/esp8266/uart.h b/ports/esp8266/uart.h
index de0919bde0..3c5592ff0a 100644
--- a/ports/esp8266/uart.h
+++ b/ports/esp8266/uart.h
@@ -101,6 +101,7 @@ bool uart_rx_wait(uint32_t timeout_us);
 int uart_rx_char(void);
 void uart_tx_one_char(uint8 uart, uint8 TxChar);
 void uart_flush(uint8 uart);
+int uart_txdone(uint8 uart);
 void uart_os_config(int uart);
 void uart_setup(uint8 uart);
 int uart0_get_rxbuf_len(void);