diff --git a/hardware/arduino/cores/arduino/CDC.cpp b/hardware/arduino/cores/arduino/CDC.cpp
index 53f86f801..e1e859d18 100644
--- a/hardware/arduino/cores/arduino/CDC.cpp
+++ b/hardware/arduino/cores/arduino/CDC.cpp
@@ -134,6 +134,10 @@ void Serial_::begin(unsigned long baud_count)
 {
 }
 
+void Serial_::begin(unsigned long baud_count, byte config)
+{
+}
+
 void Serial_::end(void)
 {
 }
diff --git a/hardware/arduino/cores/arduino/USBAPI.h b/hardware/arduino/cores/arduino/USBAPI.h
index d138a0efd..7a14285db 100644
--- a/hardware/arduino/cores/arduino/USBAPI.h
+++ b/hardware/arduino/cores/arduino/USBAPI.h
@@ -31,6 +31,7 @@ private:
 	ring_buffer *_cdc_rx_buffer;
 public:
 	void begin(unsigned long);
+	void begin(unsigned long, uint8_t);
 	void end(void);
 
 	virtual int available(void);