diff --git a/MrlMsg.h b/MrlMsg.h
index 1107a49..78084c2 100644
--- a/MrlMsg.h
+++ b/MrlMsg.h
@@ -4,6 +4,7 @@
 #include "ArduinoMsgCodec.h"
 #include "LinkedList.h"
 #include "MrlIo.h"
+#include "Arduino.h"
 
 
 // ------ error types ------
diff --git a/virtual/Arduino.h b/virtual/Arduino.h
index 6bb7ba0..2a747a4 100644
--- a/virtual/Arduino.h
+++ b/virtual/Arduino.h
@@ -1,3 +1,5 @@
+#ifndef VIRTUAL_ARDUINO_H
+#define VIRTUAL_ARDUINO_H
 
 #define NULL 0
 #define TWCR 0
@@ -5,9 +7,19 @@
 #define TCCR1B 0
 #define TCCR2B 0
 
+typedef unsigned char byte;
+
+#include "Serial.h"
+#include "Servo.h"
+#include "HardwareSerial.h"
+
 
 unsigned long micros();
 unsigned long millis();
 void digitalWrite(int pin, int value);
 void analogWrite(int pin, int value);
 void pinMode(int pin, int value);
+
+
+
+#endif VIRTUAL_ARDUINO_H