diff --git a/boards/arduino-mega2560/board.c b/boards/arduino-mega2560/board.c
index ad6d667f0e..9746555e0e 100644
--- a/boards/arduino-mega2560/board.c
+++ b/boards/arduino-mega2560/board.c
@@ -82,12 +82,14 @@ void SystemInit(void)
 
 static int uart_putchar(char c, FILE *stream)
 {
+    (void) stream;
     uart_stdio_write(&c, 1);
     return 0;
 }
 
 int uart_getchar(FILE *stream)
 {
+    (void) stream;
     char c;
     uart_stdio_read(&c, 1);
     return (int)c;