diff --git a/ArduChess.ino b/ArduChess.ino
index d7418dd..c491a34 100644
--- a/ArduChess.ino
+++ b/ArduChess.ino
@@ -1,3 +1,5 @@
+#include <Arduino.h>
+
 #include "Board.h"
 #include "Move.h"
 #include "Types.h"