diff --git a/libraries/AP_HAL_AVR_SITL/Scheduler.cpp b/libraries/AP_HAL_AVR_SITL/Scheduler.cpp
index 595d8db8fa..084d62c242 100644
--- a/libraries/AP_HAL_AVR_SITL/Scheduler.cpp
+++ b/libraries/AP_HAL_AVR_SITL/Scheduler.cpp
@@ -11,17 +11,6 @@
 #include <signal.h>
 #include <pthread.h>
 
-#ifdef __CYGWIN__
-#include <stdio.h> 
-#include <stdlib.h> 
-#include <assert.h> 
-#include <windows.h> 
-#include <string.h> 
-#include <memory.h> 
-#include <process.h> 
-#include <time.h>
-#endif
-
 using namespace AVR_SITL;
 
 extern const AP_HAL::HAL& hal;
@@ -41,11 +30,6 @@ bool SITLScheduler::_in_io_proc = false;
 
 struct timeval SITLScheduler::_sketch_start_time;
 
-#ifdef __CYGWIN__
-double SITLScheduler::_cyg_freq = 0;
-long SITLScheduler::_cyg_start = 0;
-#endif
-
 static void sigcont_handler(int)
 {
 }
@@ -63,39 +47,16 @@ SITLScheduler::SITLScheduler(SITL_State *sitlState) :
 void SITLScheduler::init(void *unused) 
 {
 	gettimeofday(&_sketch_start_time,NULL);
-
-#ifdef __CYGWIN__
-	LARGE_INTEGER lFreq, lCnt;
-	QueryPerformanceFrequency(&lFreq);
-	_cyg_freq = (double)lFreq.LowPart;
-	QueryPerformanceCounter(&lCnt);
-	_cyg_start = lCnt.LowPart;
-#endif
-
 }
-#ifdef __CYGWIN__
-double SITLScheduler::_cyg_sec()
-{
-	LARGE_INTEGER lCnt;
-	long tcnt;
-	QueryPerformanceCounter(&lCnt);
- 	tcnt = lCnt.LowPart - _cyg_start;
- 	return ((double)tcnt) / _cyg_freq;
-}
-#endif
 
 uint64_t SITLScheduler::_micros64() 
 {
-#ifdef __CYGWIN__
-	return (uint64_t)(_cyg_sec() * 1.0e6);
-#else   
 	struct timeval tp;
 	gettimeofday(&tp,NULL);
 	uint64_t ret = 1.0e6*((tp.tv_sec + (tp.tv_usec*1.0e-6)) - 
                           (_sketch_start_time.tv_sec +
                            (_sketch_start_time.tv_usec*1.0e-6)));
     return ret;
-#endif
 }
 
 uint64_t SITLScheduler::micros64() 
@@ -116,17 +77,12 @@ uint64_t SITLScheduler::millis64()
     if (stopped_clock_usec) {
         return stopped_clock_usec/1000;
     }
-#ifdef __CYGWIN__
-	// 1000 ms in a second
-	return (uint64_t)(_cyg_sec() * 1000);
-#else
 	struct timeval tp;
 	gettimeofday(&tp,NULL);
 	uint64_t ret = 1.0e3*((tp.tv_sec + (tp.tv_usec*1.0e-6)) - 
                           (_sketch_start_time.tv_sec +
                            (_sketch_start_time.tv_usec*1.0e-6)));
     return ret;
-#endif
 }
 
 uint32_t SITLScheduler::millis()