diff --git a/libraries/AP_HAL_ChibiOS/UARTDriver.cpp b/libraries/AP_HAL_ChibiOS/UARTDriver.cpp
index 430e70a0bc..888f9a6671 100644
--- a/libraries/AP_HAL_ChibiOS/UARTDriver.cpp
+++ b/libraries/AP_HAL_ChibiOS/UARTDriver.cpp
@@ -564,6 +564,24 @@ uint32_t UARTDriver::txspace()
     return _writebuf.space();
 }
 
+bool UARTDriver::discard_input()
+{
+    if (lock_read_key != 0 || _uart_owner_thd != chThdGetSelfX()){
+        return false;
+    }
+    if (!_initialised) {
+        return false;
+    }
+
+    _readbuf.empty();
+
+    if (!_rts_is_active) {
+        update_rts_line();
+    }
+
+    return true;
+}
+
 int16_t UARTDriver::read()
 {
     if (lock_read_key != 0 || _uart_owner_thd != chThdGetSelfX()){
diff --git a/libraries/AP_HAL_ChibiOS/UARTDriver.h b/libraries/AP_HAL_ChibiOS/UARTDriver.h
index 63832b051d..7ebf4d5d02 100644
--- a/libraries/AP_HAL_ChibiOS/UARTDriver.h
+++ b/libraries/AP_HAL_ChibiOS/UARTDriver.h
@@ -47,6 +47,8 @@ public:
     int16_t read_locked(uint32_t key) override;
     void _timer_tick(void) override;
 
+    bool discard_input() override;
+
     size_t write(uint8_t c) override;
     size_t write(const uint8_t *buffer, size_t size) override;