diff --git a/common_windows.go b/common_windows.go
index 41a123f..d319f7e 100644
--- a/common_windows.go
+++ b/common_windows.go
@@ -88,7 +88,6 @@ var (
 	_createWindowEx = user32.NewProc("CreateWindowExW")
 	_getClientRect = user32.NewProc("GetClientRect")
 	_moveWindow = user32.NewProc("MoveWindow")
-	_setWindowLong = user32.NewProc("SetWindowLongW")
 	_setWindowPos = user32.NewProc("SetWindowPos")
 	_setWindowText = user32.NewProc("SetWindowTextW")
 	_showWindow = user32.NewProc("ShowWindow")
diff --git a/sysdata_windows.go b/sysdata_windows.go
index 021b80a..8d858a1 100644
--- a/sysdata_windows.go
+++ b/sysdata_windows.go
@@ -545,7 +545,7 @@ func (s *sysData) setIndeterminate() {
 	ret := make(chan uiret)
 	defer close(ret)
 	uitask <- &uimsg{
-		call:		_setWindowLong,
+		call:		_setWindowLongPtr,
 		p:		[]uintptr{
 			uintptr(s.hwnd),
 			negConst(_GWL_STYLE),
@@ -592,7 +592,7 @@ func (s *sysData) setProgress(percent int) {
 		}
 		<-ret
 		uitask <- &uimsg{
-			call:		_setWindowLong,
+			call:		_setWindowLongPtr,
 			p:		[]uintptr{
 				uintptr(s.hwnd),
 				negConst(_GWL_STYLE),