diff --git a/Marlin/src/HAL/HAL_DUE/MarlinSerialUSB_Due.cpp b/Marlin/src/HAL/HAL_DUE/MarlinSerialUSB_Due.cpp
index 4f6b4915fa..7b1100dd9d 100644
--- a/Marlin/src/HAL/HAL_DUE/MarlinSerialUSB_Due.cpp
+++ b/Marlin/src/HAL/HAL_DUE/MarlinSerialUSB_Due.cpp
@@ -114,8 +114,8 @@ bool MarlinSerialUSB::available(void) {
       (usb_task_cdc_isenabled() && udi_cdc_is_rx_ready());
 }
 
-void MarlinSerialUSB::flush(void) {
-}
+void MarlinSerialUSB::flush(void) { }
+void MarlinSerialUSB::flushTX(void) { }
 
 void MarlinSerialUSB::write(const uint8_t c) {
 
diff --git a/Marlin/src/HAL/HAL_DUE/MarlinSerialUSB_Due.h b/Marlin/src/HAL/HAL_DUE/MarlinSerialUSB_Due.h
index 65f829e2a1..5025b82284 100644
--- a/Marlin/src/HAL/HAL_DUE/MarlinSerialUSB_Due.h
+++ b/Marlin/src/HAL/HAL_DUE/MarlinSerialUSB_Due.h
@@ -46,6 +46,7 @@ public:
   static int peek(void);
   static int read(void);
   static void flush(void);
+  static void flushTX(void);
   static bool available(void);
   static void write(const uint8_t c);