diff --git a/src/Timer.cpp b/src/Timer.cpp
index a555aeb..3c97c7c 100644
--- a/src/Timer.cpp
+++ b/src/Timer.cpp
@@ -23,7 +23,7 @@
 
 #include "Timer.h"
 
-#ifdef _WIN32
+#ifdef WIN32
 	#include <mmsystem.h>
 #endif
 
@@ -97,7 +97,7 @@ void Timer::update(void)
 	}
 	else
 	{
-#ifdef _WIN32
+#ifdef WIN32
 		system_milliseconds = timeGetTime ();
 #else
 		gettimeofday(&time_val,&time_zone);
diff --git a/src/Timer.h b/src/Timer.h
index 64500b0..914a470 100644
--- a/src/Timer.h
+++ b/src/Timer.h
@@ -24,9 +24,10 @@
 #ifndef TIMER_H
 #define TIMER_H
 
-#ifndef _WIN32
+#ifndef WIN32
 #include <sys/time.h>
 #endif
+#include <windows.h>
 
 /// Timer Class, high resolution timer
 /**
@@ -46,7 +47,7 @@ private:
 	unsigned long paused_time;
 	unsigned long offset;
 
-#ifndef _WIN32
+#ifndef WIN32
 	struct timeval time_val;
 	struct timezone time_zone;                                                                                            
 #endif