diff --git a/hardware/arduino/avr/cores/arduino/HardwareSerial.cpp b/hardware/arduino/avr/cores/arduino/HardwareSerial.cpp
index a5a346245..28a3ef601 100644
--- a/hardware/arduino/avr/cores/arduino/HardwareSerial.cpp
+++ b/hardware/arduino/avr/cores/arduino/HardwareSerial.cpp
@@ -284,7 +284,6 @@ HardwareSerial::HardwareSerial(
 void HardwareSerial::begin(unsigned long baud, byte config)
 {
   uint16_t baud_setting;
-  uint8_t current_config;
   bool use_u2x = true;
 
 #if F_CPU == 16000000UL