diff --git a/libusbK/src/lusbk_bknd_libusb0.c b/libusbK/src/lusbk_bknd_libusb0.c
index 57333bd..775be76 100644
--- a/libusbK/src/lusbk_bknd_libusb0.c
+++ b/libusbK/src/lusbk_bknd_libusb0.c
@@ -50,12 +50,10 @@ KUSB_EXP BOOL KUSB_API LUsb0_ControlTransfer(
 	int ret;
 	PKUSB_HANDLE_INTERNAL handle;
 
-	UNUSED(Overlapped);
-
 	Pub_To_Priv_UsbK(InterfaceHandle, handle, return FALSE);
 	ErrorSetAction(!PoolHandle_Inc_UsbK(handle), ERROR_RESOURCE_NOT_AVAILABLE, return FALSE, "->PoolHandle_Inc_UsbK");
 
-	ret = usb_control_msg(Dev_Handle(), SetupPacket.RequestType, SetupPacket.Request, SetupPacket.Value, SetupPacket.Index, Buffer, BufferLength, LIBUSB_DEFAULT_TIMEOUT);
+	ret = usb_control_msg(Dev_Handle(), SetupPacket.RequestType, SetupPacket.Request, SetupPacket.Value, SetupPacket.Index, Buffer, BufferLength, LIBUSB_DEFAULT_TIMEOUT, Overlapped);
 
 	if (ret >= 0)
 	{
@@ -119,7 +117,7 @@ int usb_set_configuration(HANDLE *dev, int configuration)
 	req.timeout = LIBUSB_DEFAULT_TIMEOUT;
 
 	if (!_usb_io_sync(dev, LIBUSB_IOCTL_SET_CONFIGURATION,
-		&req, sizeof(libusb_request), NULL, 0, NULL))
+		&req, sizeof(libusb_request), NULL, 0, NULL, NULL))
 	{
 		USBERR("could not set config %d: ", configuration);
 		return FALSE;
@@ -130,7 +128,8 @@ int usb_set_configuration(HANDLE *dev, int configuration)
 
 // See libusb-win32 windows.c:671-815
 int usb_control_msg(HANDLE *dev, int requesttype, int request,
-	int value, int index, PUCHAR bytes, int size, int timeout)
+	int value, int index, PUCHAR bytes, int size, int timeout,
+	LPOVERLAPPED Overlapped)
 {
 	int read = 0;
 	libusb_request req;
@@ -255,7 +254,8 @@ int usb_control_msg(HANDLE *dev, int requesttype, int request,
 		in_size = 0;
 	}
 
-	if (!_usb_io_sync(dev, code, out, out_size, in, in_size, &read))
+	if (!_usb_io_sync(dev, code, out, out_size, in, in_size, &read,
+			  Overlapped))
 	{
 		USBERR("sending control message failed");
 		if (!(requesttype & USB_ENDPOINT_IN))
@@ -276,9 +276,10 @@ int usb_control_msg(HANDLE *dev, int requesttype, int request,
 }
 
 int _usb_io_sync(HANDLE dev, unsigned int code, void *out, int out_size,
-	void *in, int in_size, int *ret)
+	void *in, int in_size, int *ret, LPOVERLAPPED Overlapped)
 {
 	OVERLAPPED ol;
+	OVERLAPPED *olp;
 	DWORD _ret;
 
 	memset(&ol, 0, sizeof(ol));
@@ -286,28 +287,42 @@ int _usb_io_sync(HANDLE dev, unsigned int code, void *out, int out_size,
 	if (ret)
 		*ret = 0;
 
-	ol.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+	if (!Overlapped)
+	{
+		ol.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
 
-	if (!ol.hEvent)
-		return FALSE;
+		if (!ol.hEvent)
+			return FALSE;
+
+		olp = &ol;
+	}
+	else
+	{
+		olp = Overlapped;
+	}
 
-	if (!DeviceIoControl(dev, code, out, out_size, in, in_size, NULL, &ol))
+	if (!DeviceIoControl(dev, code, out, out_size, in, in_size, NULL, olp))
 	{
 		if (GetLastError() != ERROR_IO_PENDING)
 		{
-			CloseHandle(ol.hEvent);
+			USBERR("DeviceIoControl failed");
+			if (!Overlapped)
+				CloseHandle(ol.hEvent);
 			return FALSE;
 		}
 	}
 
-	if (GetOverlappedResult(dev, &ol, &_ret, TRUE))
+	if (GetOverlappedResult(dev, olp, &_ret, TRUE))
 	{
 		if (ret)
 			*ret = (int)_ret;
-		CloseHandle(ol.hEvent);
+		if (!Overlapped)
+			CloseHandle(ol.hEvent);
 		return TRUE;
 	}
 
-	CloseHandle(ol.hEvent);
+	USBERR("GetOverlappedResult failed");
+	if (!Overlapped)
+		CloseHandle(ol.hEvent);
 	return FALSE;
-}
\ No newline at end of file
+}
diff --git a/libusbK/src/lusbk_bknd_libusb0.h b/libusbK/src/lusbk_bknd_libusb0.h
index 441f293..34a96f6 100644
--- a/libusbK/src/lusbk_bknd_libusb0.h
+++ b/libusbK/src/lusbk_bknd_libusb0.h
@@ -27,9 +27,10 @@ binary distributions.
 #endif
 
 int _usb_io_sync(HANDLE dev, unsigned int code, void *out, int out_size,
-	void *in, int in_size, int *ret);
+	void *in, int in_size, int *ret, LPOVERLAPPED Overlapped);
 
 int usb_control_msg(HANDLE *dev, int requesttype, int request,
-	int value, int index, PUCHAR bytes, int size, int timeout);
+	int value, int index, PUCHAR bytes, int size, int timeout,
+	LPOVERLAPPED Overlapped);
 
-int usb_set_configuration(HANDLE *dev, int configuration);
\ No newline at end of file
+int usb_set_configuration(HANDLE *dev, int configuration);