diff --git a/cores/esp32/HardwareSerial.cpp b/cores/esp32/HardwareSerial.cpp
index d0d83bd34387b900b70088f166db8fd4f0a98ad9..c449b1640e76d43ef51ce418962334689d9a7a86 100644
--- a/cores/esp32/HardwareSerial.cpp
+++ b/cores/esp32/HardwareSerial.cpp
@@ -62,6 +62,10 @@ int HardwareSerial::available(void)
 {
     return uartAvailable(_uart);
 }
+int HardwareSerial::availableForWrite(void)
+{
+    return uartAvailableForWrite(_uart);
+}
 
 int HardwareSerial::peek(void)
 {
diff --git a/cores/esp32/HardwareSerial.h b/cores/esp32/HardwareSerial.h
index f1a9d36ca1a0c088d21b4e8556fccd1012eb9704..c0e00ec2e23699c75f947e5d6b4d2b4e74835467 100644
--- a/cores/esp32/HardwareSerial.h
+++ b/cores/esp32/HardwareSerial.h
@@ -40,6 +40,7 @@ public:
     void begin(unsigned long baud, uint32_t config=SERIAL_8N1, int8_t rxPin=-1, int8_t txPin=-1, bool invert=false);
     void end();
     int available(void);
+    int availableForWrite(void);
     int peek(void);
     int read(void);
     void flush(void);
diff --git a/cores/esp32/esp32-hal-uart.c b/cores/esp32/esp32-hal-uart.c
index 6612668901bb3134b31804bfa2a2205bb4ca29c7..bcf9d0450931ba740e93c28a4afc96dbba49ace1 100644
--- a/cores/esp32/esp32-hal-uart.c
+++ b/cores/esp32/esp32-hal-uart.c
@@ -248,6 +248,14 @@ uint32_t uartAvailable(uart_t* uart)
     return uxQueueMessagesWaiting(uart->queue);
 }
 
+uint32_t uartAvailableForWrite(uart_t* uart)
+{
+    if(uart == NULL) {
+        return 0;
+    }
+    return 0x7f - uart->dev->status.txfifo_cnt;
+}
+
 uint8_t uartRead(uart_t* uart)
 {
     if(uart == NULL || uart->queue == NULL) {
diff --git a/cores/esp32/esp32-hal-uart.h b/cores/esp32/esp32-hal-uart.h
index ce83f1461c7b338df78da0d5a0a606e30c1d4650..5cd6e965099d709d15de87465e1582abb0e49a7b 100644
--- a/cores/esp32/esp32-hal-uart.h
+++ b/cores/esp32/esp32-hal-uart.h
@@ -55,6 +55,7 @@ uart_t* uartBegin(uint8_t uart_nr, uint32_t baudrate, uint32_t config, int8_t rx
 void uartEnd(uart_t* uart);
 
 uint32_t uartAvailable(uart_t* uart);
+uint32_t uartAvailableForWrite(uart_t* uart);
 uint8_t uartRead(uart_t* uart);
 uint8_t uartPeek(uart_t* uart);