diff --git a/src/pkg/exp/wingui/gui.go b/src/pkg/exp/wingui/gui.go
index cf392934c5b..a2f16f282b1 100644
--- a/src/pkg/exp/wingui/gui.go
+++ b/src/pkg/exp/wingui/gui.go
@@ -25,13 +25,12 @@ func abortErrNo(funcname string, err int) {
 // global vars
 
 var (
-	mh uint32
-	bh uint32
+	mh syscall.Handle
+	bh syscall.Handle
 )
 
 // WinProc called by windows to notify us of all windows events we might be interested in.
-func WndProc(hwnd, msg uint32, wparam, lparam int32) uintptr {
-	var rc int32
+func WndProc(hwnd syscall.Handle, msg uint32, wparam, lparam uintptr) (rc uintptr) {
 	switch msg {
 	case WM_CREATE:
 		var e int
@@ -49,7 +48,7 @@ func WndProc(hwnd, msg uint32, wparam, lparam int32) uintptr {
 		fmt.Printf("button handle is %x\n", bh)
 		rc = DefWindowProc(hwnd, msg, wparam, lparam)
 	case WM_COMMAND:
-		switch uint32(lparam) {
+		switch syscall.Handle(lparam) {
 		case bh:
 			e := PostMessage(hwnd, WM_CLOSE, 0, 0)
 			if e != 0 {
@@ -66,7 +65,7 @@ func WndProc(hwnd, msg uint32, wparam, lparam int32) uintptr {
 		rc = DefWindowProc(hwnd, msg, wparam, lparam)
 	}
 	//fmt.Printf("WndProc(0x%08x, %d, 0x%08x, 0x%08x) (%d)\n", hwnd, msg, wparam, lparam, rc)
-	return uintptr(rc)
+	return
 }
 
 func rungui() int {
diff --git a/src/pkg/exp/wingui/winapi.go b/src/pkg/exp/wingui/winapi.go
index 31b57a2cc86..32015287c92 100644
--- a/src/pkg/exp/wingui/winapi.go
+++ b/src/pkg/exp/wingui/winapi.go
@@ -6,6 +6,7 @@ package main
 
 import (
 	"unsafe"
+	"syscall"
 )
 
 type Wndclassex struct {
@@ -14,25 +15,25 @@ type Wndclassex struct {
 	WndProc    uintptr
 	ClsExtra   int32
 	WndExtra   int32
-	Instance   uint32
-	Icon       uint32
-	Cursor     uint32
-	Background uint32
+	Instance   syscall.Handle
+	Icon       syscall.Handle
+	Cursor     syscall.Handle
+	Background syscall.Handle
 	MenuName   *uint16
 	ClassName  *uint16
-	IconSm     uint32
+	IconSm     syscall.Handle
 }
 
 type Point struct {
-	X int32
-	Y int32
+	X uintptr
+	Y uintptr
 }
 
 type Msg struct {
-	Hwnd    uint32
+	Hwnd    syscall.Handle
 	Message uint32
-	Wparam  int32
-	Lparam  int32
+	Wparam  uintptr
+	Lparam  uintptr
 	Time    uint32
 	Pt      Point
 }
@@ -109,22 +110,22 @@ var (
 	IDI_INFORMATION = IDI_ASTERISK
 )
 
-//sys	GetModuleHandle(modname *uint16) (handle uint32, errno int) = GetModuleHandleW
+//sys	GetModuleHandle(modname *uint16) (handle syscall.Handle, errno int) = GetModuleHandleW
 //sys	RegisterClassEx(wndclass *Wndclassex) (atom uint16, errno int) = user32.RegisterClassExW
-//sys	CreateWindowEx(exstyle uint32, classname *uint16, windowname *uint16, style uint32, x int32, y int32, width int32, height int32, wndparent uint32, menu uint32, instance uint32, param uintptr) (hwnd uint32, errno int) = user32.CreateWindowExW
-//sys	DefWindowProc(hwnd uint32, msg uint32, wparam int32, lparam int32) (lresult int32) = user32.DefWindowProcW
-//sys	DestroyWindow(hwnd uint32) (errno int) = user32.DestroyWindow
+//sys	CreateWindowEx(exstyle uint32, classname *uint16, windowname *uint16, style uint32, x int32, y int32, width int32, height int32, wndparent syscall.Handle, menu syscall.Handle, instance syscall.Handle, param uintptr) (hwnd syscall.Handle, errno int) = user32.CreateWindowExW
+//sys	DefWindowProc(hwnd syscall.Handle, msg uint32, wparam uintptr, lparam uintptr) (lresult uintptr) = user32.DefWindowProcW
+//sys	DestroyWindow(hwnd syscall.Handle) (errno int) = user32.DestroyWindow
 //sys	PostQuitMessage(exitcode int32) = user32.PostQuitMessage
-//sys	ShowWindow(hwnd uint32, cmdshow int32) (wasvisible bool) = user32.ShowWindow
-//sys	UpdateWindow(hwnd uint32) (errno int) = user32.UpdateWindow
-//sys	GetMessage(msg *Msg, hwnd uint32, MsgFilterMin uint32, MsgFilterMax uint32) (ret int32, errno int) [failretval==-1] = user32.GetMessageW
+//sys	ShowWindow(hwnd syscall.Handle, cmdshow int32) (wasvisible bool) = user32.ShowWindow
+//sys	UpdateWindow(hwnd syscall.Handle) (errno int) = user32.UpdateWindow
+//sys	GetMessage(msg *Msg, hwnd syscall.Handle, MsgFilterMin uint32, MsgFilterMax uint32) (ret int32, errno int) [failretval==-1] = user32.GetMessageW
 //sys	TranslateMessage(msg *Msg) (done bool) = user32.TranslateMessage
 //sys	DispatchMessage(msg *Msg) (ret int32) = user32.DispatchMessageW
-//sys	LoadIcon(instance uint32, iconname *uint16) (icon uint32, errno int) = user32.LoadIconW
-//sys	LoadCursor(instance uint32, cursorname *uint16) (cursor uint32, errno int) = user32.LoadCursorW
-//sys	SetCursor(cursor uint32) (precursor uint32, errno int) = user32.SetCursor
-//sys	SendMessage(hwnd uint32, msg uint32, wparam int32, lparam int32) (lresult int32) = user32.SendMessageW
-//sys	PostMessage(hwnd uint32, msg uint32, wparam int32, lparam int32) (errno int) = user32.PostMessageW
+//sys	LoadIcon(instance syscall.Handle, iconname *uint16) (icon syscall.Handle, errno int) = user32.LoadIconW
+//sys	LoadCursor(instance syscall.Handle, cursorname *uint16) (cursor syscall.Handle, errno int) = user32.LoadCursorW
+//sys	SetCursor(cursor syscall.Handle) (precursor syscall.Handle, errno int) = user32.SetCursor
+//sys	SendMessage(hwnd syscall.Handle, msg uint32, wparam uintptr, lparam uintptr) (lresult uintptr) = user32.SendMessageW
+//sys	PostMessage(hwnd syscall.Handle, msg uint32, wparam uintptr, lparam uintptr) (errno int) = user32.PostMessageW
 
 func MakeIntResource(id uint16) *uint16 {
 	return (*uint16)(unsafe.Pointer(uintptr(id)))
diff --git a/src/pkg/exp/wingui/zwinapi.go b/src/pkg/exp/wingui/zwinapi.go
index 4c009dd69bc..38e93eea717 100644
--- a/src/pkg/exp/wingui/zwinapi.go
+++ b/src/pkg/exp/wingui/zwinapi.go
@@ -28,9 +28,9 @@ var (
 	procPostMessageW     = moduser32.NewProc("PostMessageW")
 )
 
-func GetModuleHandle(modname *uint16) (handle uint32, errno int) {
+func GetModuleHandle(modname *uint16) (handle syscall.Handle, errno int) {
 	r0, _, e1 := syscall.Syscall(procGetModuleHandleW.Addr(), 1, uintptr(unsafe.Pointer(modname)), 0, 0)
-	handle = uint32(r0)
+	handle = syscall.Handle(r0)
 	if handle == 0 {
 		if e1 != 0 {
 			errno = int(e1)
@@ -58,9 +58,9 @@ func RegisterClassEx(wndclass *Wndclassex) (atom uint16, errno int) {
 	return
 }
 
-func CreateWindowEx(exstyle uint32, classname *uint16, windowname *uint16, style uint32, x int32, y int32, width int32, height int32, wndparent uint32, menu uint32, instance uint32, param uintptr) (hwnd uint32, errno int) {
+func CreateWindowEx(exstyle uint32, classname *uint16, windowname *uint16, style uint32, x int32, y int32, width int32, height int32, wndparent syscall.Handle, menu syscall.Handle, instance syscall.Handle, param uintptr) (hwnd syscall.Handle, errno int) {
 	r0, _, e1 := syscall.Syscall12(procCreateWindowExW.Addr(), 12, uintptr(exstyle), uintptr(unsafe.Pointer(classname)), uintptr(unsafe.Pointer(windowname)), uintptr(style), uintptr(x), uintptr(y), uintptr(width), uintptr(height), uintptr(wndparent), uintptr(menu), uintptr(instance), uintptr(param))
-	hwnd = uint32(r0)
+	hwnd = syscall.Handle(r0)
 	if hwnd == 0 {
 		if e1 != 0 {
 			errno = int(e1)
@@ -73,13 +73,13 @@ func CreateWindowEx(exstyle uint32, classname *uint16, windowname *uint16, style
 	return
 }
 
-func DefWindowProc(hwnd uint32, msg uint32, wparam int32, lparam int32) (lresult int32) {
+func DefWindowProc(hwnd syscall.Handle, msg uint32, wparam uintptr, lparam uintptr) (lresult uintptr) {
 	r0, _, _ := syscall.Syscall6(procDefWindowProcW.Addr(), 4, uintptr(hwnd), uintptr(msg), uintptr(wparam), uintptr(lparam), 0, 0)
-	lresult = int32(r0)
+	lresult = uintptr(r0)
 	return
 }
 
-func DestroyWindow(hwnd uint32) (errno int) {
+func DestroyWindow(hwnd syscall.Handle) (errno int) {
 	r1, _, e1 := syscall.Syscall(procDestroyWindow.Addr(), 1, uintptr(hwnd), 0, 0)
 	if int(r1) == 0 {
 		if e1 != 0 {
@@ -98,13 +98,13 @@ func PostQuitMessage(exitcode int32) {
 	return
 }
 
-func ShowWindow(hwnd uint32, cmdshow int32) (wasvisible bool) {
+func ShowWindow(hwnd syscall.Handle, cmdshow int32) (wasvisible bool) {
 	r0, _, _ := syscall.Syscall(procShowWindow.Addr(), 2, uintptr(hwnd), uintptr(cmdshow), 0)
 	wasvisible = bool(r0 != 0)
 	return
 }
 
-func UpdateWindow(hwnd uint32) (errno int) {
+func UpdateWindow(hwnd syscall.Handle) (errno int) {
 	r1, _, e1 := syscall.Syscall(procUpdateWindow.Addr(), 1, uintptr(hwnd), 0, 0)
 	if int(r1) == 0 {
 		if e1 != 0 {
@@ -118,7 +118,7 @@ func UpdateWindow(hwnd uint32) (errno int) {
 	return
 }
 
-func GetMessage(msg *Msg, hwnd uint32, MsgFilterMin uint32, MsgFilterMax uint32) (ret int32, errno int) {
+func GetMessage(msg *Msg, hwnd syscall.Handle, MsgFilterMin uint32, MsgFilterMax uint32) (ret int32, errno int) {
 	r0, _, e1 := syscall.Syscall6(procGetMessageW.Addr(), 4, uintptr(unsafe.Pointer(msg)), uintptr(hwnd), uintptr(MsgFilterMin), uintptr(MsgFilterMax), 0, 0)
 	ret = int32(r0)
 	if ret == -1 {
@@ -145,9 +145,9 @@ func DispatchMessage(msg *Msg) (ret int32) {
 	return
 }
 
-func LoadIcon(instance uint32, iconname *uint16) (icon uint32, errno int) {
+func LoadIcon(instance syscall.Handle, iconname *uint16) (icon syscall.Handle, errno int) {
 	r0, _, e1 := syscall.Syscall(procLoadIconW.Addr(), 2, uintptr(instance), uintptr(unsafe.Pointer(iconname)), 0)
-	icon = uint32(r0)
+	icon = syscall.Handle(r0)
 	if icon == 0 {
 		if e1 != 0 {
 			errno = int(e1)
@@ -160,9 +160,9 @@ func LoadIcon(instance uint32, iconname *uint16) (icon uint32, errno int) {
 	return
 }
 
-func LoadCursor(instance uint32, cursorname *uint16) (cursor uint32, errno int) {
+func LoadCursor(instance syscall.Handle, cursorname *uint16) (cursor syscall.Handle, errno int) {
 	r0, _, e1 := syscall.Syscall(procLoadCursorW.Addr(), 2, uintptr(instance), uintptr(unsafe.Pointer(cursorname)), 0)
-	cursor = uint32(r0)
+	cursor = syscall.Handle(r0)
 	if cursor == 0 {
 		if e1 != 0 {
 			errno = int(e1)
@@ -175,9 +175,9 @@ func LoadCursor(instance uint32, cursorname *uint16) (cursor uint32, errno int)
 	return
 }
 
-func SetCursor(cursor uint32) (precursor uint32, errno int) {
+func SetCursor(cursor syscall.Handle) (precursor syscall.Handle, errno int) {
 	r0, _, e1 := syscall.Syscall(procSetCursor.Addr(), 1, uintptr(cursor), 0, 0)
-	precursor = uint32(r0)
+	precursor = syscall.Handle(r0)
 	if precursor == 0 {
 		if e1 != 0 {
 			errno = int(e1)
@@ -190,13 +190,13 @@ func SetCursor(cursor uint32) (precursor uint32, errno int) {
 	return
 }
 
-func SendMessage(hwnd uint32, msg uint32, wparam int32, lparam int32) (lresult int32) {
+func SendMessage(hwnd syscall.Handle, msg uint32, wparam uintptr, lparam uintptr) (lresult uintptr) {
 	r0, _, _ := syscall.Syscall6(procSendMessageW.Addr(), 4, uintptr(hwnd), uintptr(msg), uintptr(wparam), uintptr(lparam), 0, 0)
-	lresult = int32(r0)
+	lresult = uintptr(r0)
 	return
 }
 
-func PostMessage(hwnd uint32, msg uint32, wparam int32, lparam int32) (errno int) {
+func PostMessage(hwnd syscall.Handle, msg uint32, wparam uintptr, lparam uintptr) (errno int) {
 	r1, _, e1 := syscall.Syscall6(procPostMessageW.Addr(), 4, uintptr(hwnd), uintptr(msg), uintptr(wparam), uintptr(lparam), 0, 0)
 	if int(r1) == 0 {
 		if e1 != 0 {
diff --git a/src/pkg/syscall/syscall_windows.go b/src/pkg/syscall/syscall_windows.go
index 19c6587f526..30df718491f 100644
--- a/src/pkg/syscall/syscall_windows.go
+++ b/src/pkg/syscall/syscall_windows.go
@@ -158,7 +158,7 @@ func NewCallback(fn interface{}) uintptr
 //sys	GetLastError() (lasterrno int)
 //sys	LoadLibrary(libname string) (handle Handle, errno int) = LoadLibraryW
 //sys	FreeLibrary(handle Handle) (errno int)
-//sys	GetProcAddress(module Handle, procname string) (proc Handle, errno int)
+//sys	GetProcAddress(module Handle, procname string) (proc uintptr, errno int)
 //sys	GetVersion() (ver uint32, errno int)
 //sys	FormatMessage(flags uint32, msgsrc uint32, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, errno int) = FormatMessageW
 //sys	ExitProcess(exitcode uint32)
diff --git a/src/pkg/syscall/zsyscall_windows_386.go b/src/pkg/syscall/zsyscall_windows_386.go
index b46493f8dd1..b7e9f606c3e 100644
--- a/src/pkg/syscall/zsyscall_windows_386.go
+++ b/src/pkg/syscall/zsyscall_windows_386.go
@@ -141,9 +141,8 @@ func FreeLibrary(handle Handle) (errno int) {
 	return
 }
 
-func GetProcAddress(module Handle, procname string) (proc Handle, errno int) {
-	r0, _, e1 := Syscall(procGetProcAddress.Addr(), 2, uintptr(module), uintptr(unsafe.Pointer(StringBytePtr(procname))), 0)
-	proc = Handle(r0)
+func GetProcAddress(module Handle, procname string) (proc uintptr, errno int) {
+	proc, _, e1 := Syscall(procGetProcAddress.Addr(), 2, uintptr(module), uintptr(unsafe.Pointer(StringBytePtr(procname))), 0)
 	if proc == 0 {
 		if e1 != 0 {
 			errno = int(e1)
diff --git a/src/pkg/syscall/zsyscall_windows_amd64.go b/src/pkg/syscall/zsyscall_windows_amd64.go
index ca087bb69c3..a791130e0a5 100644
--- a/src/pkg/syscall/zsyscall_windows_amd64.go
+++ b/src/pkg/syscall/zsyscall_windows_amd64.go
@@ -141,9 +141,8 @@ func FreeLibrary(handle Handle) (errno int) {
 	return
 }
 
-func GetProcAddress(module Handle, procname string) (proc Handle, errno int) {
-	r0, _, e1 := Syscall(procGetProcAddress.Addr(), 2, uintptr(module), uintptr(unsafe.Pointer(StringBytePtr(procname))), 0)
-	proc = Handle(r0)
+func GetProcAddress(module Handle, procname string) (proc uintptr, errno int) {
+	proc, _, e1 := Syscall(procGetProcAddress.Addr(), 2, uintptr(module), uintptr(unsafe.Pointer(StringBytePtr(procname))), 0)
 	if proc == 0 {
 		if e1 != 0 {
 			errno = int(e1)