diff --git a/area_windows.go b/area_windows.go
index 6daf4bf..5d62291 100644
--- a/area_windows.go
+++ b/area_windows.go
@@ -67,21 +67,9 @@ var (
 
 const (
 	areaBackgroundBrush = _HBRUSH(_COLOR_BTNFACE + 1)
-
-	// from winuser.h
-	_WM_PAINT = 0x000F
 )
 
 func paintArea(s *sysData) {
-	const (
-		// from wingdi.h
-		_BI_RGB = 0
-		_DIB_RGB_COLORS = 0
-		_SRCCOPY = 0x00CC0020
-		_AC_SRC_OVER = 0x00
-		_AC_SRC_ALPHA = 0x01
-	)
-
 	var xrect _RECT
 	var ps _PAINTSTRUCT
 
@@ -459,11 +447,6 @@ func getModifiers() (m Modifiers) {
 	return m
 }
 
-const (
-	_SM_CXDOUBLECLK = 36
-	_SM_CYDOUBLECLK = 37
-)
-
 var (
 	_getMessageTime = user32.NewProc("GetMessageTime")
 	_getDoubleClickTime = user32.NewProc("GetDoubleClickTime")
@@ -603,10 +586,6 @@ var (
 
 func areaWndProc(s *sysData) func(hwnd _HWND, uMsg uint32, wParam _WPARAM, lParam _LPARAM) _LRESULT {
 	return func(hwnd _HWND, uMsg uint32, wParam _WPARAM, lParam _LPARAM) _LRESULT {
-		const (
-			_MA_ACTIVATE = 1
-		)
-
 		defwndproc := func() _LRESULT {
 			r1, _, _ := defWindowProc.Call(
 				uintptr(hwnd),
@@ -722,11 +701,6 @@ func areaWndProc(s *sysData) func(hwnd _HWND, uMsg uint32, wParam _WPARAM, lPara
 }
 
 func registerAreaWndClass(s *sysData) (newClassName string, err error) {
-	const (
-		_CS_HREDRAW = 0x0002
-		_CS_VREDRAW = 0x0001
-	)
-
 	areaWndClassNumLock.Lock()
 	newClassName = fmt.Sprintf(areaWndClassFormat, areaWndClassNum)
 	areaWndClassNum++
diff --git a/zconstants_windows_386.go b/zconstants_windows_386.go
index 3a63ddd..fcbdce0 100644
--- a/zconstants_windows_386.go
+++ b/zconstants_windows_386.go
@@ -1,6 +1,9 @@
 // autogenerated by windowsconstgen; do not edit
 package ui
+const _AC_SRC_ALPHA = 1
+const _AC_SRC_OVER = 0
 const _BCM_GETIDEALSIZE = 5633
+const _BI_RGB = 0
 const _BM_GETCHECK = 240
 const _BN_CLICKED = 0
 const _BST_CHECKED = 1
@@ -17,7 +20,10 @@ const _CB_GETCOUNT = 326
 const _CB_GETCURSEL = 327
 const _CB_INSERTSTRING = 330
 const _COLOR_BTNFACE = 15
+const _CS_HREDRAW = 2
+const _CS_VREDRAW = 1
 const _CW_USEDEFAULT = -2147483648
+const _DIB_RGB_COLORS = 0
 const _ERROR = 0
 const _ES_AUTOHSCROLL = 128
 const _ES_PASSWORD = 32
@@ -37,6 +43,7 @@ const _LB_GETSELITEMS = 401
 const _LB_GETTEXT = 393
 const _LB_GETTEXTLEN = 394
 const _LB_INSERTSTRING = 385
+const _MA_ACTIVATE = 1
 const _MB_ICONERROR = 16
 const _MB_OK = 0
 const _MK_LBUTTON = 1
@@ -62,6 +69,9 @@ const _SIF_PAGE = 2
 const _SIF_POS = 4
 const _SIF_RANGE = 1
 const _SIF_TRACKPOS = 16
+const _SM_CXDOUBLECLK = 36
+const _SM_CYDOUBLECLK = 37
+const _SRCCOPY = 13369376
 const _SS_LEFTNOWORDWRAP = 12
 const _SS_NOPREFIX = 128
 const _SW_ERASE = 4
@@ -117,6 +127,7 @@ const _WM_MBUTTONDOWN = 519
 const _WM_MBUTTONUP = 520
 const _WM_MOUSEACTIVATE = 33
 const _WM_MOUSEMOVE = 512
+const _WM_PAINT = 15
 const _WM_RBUTTONDOWN = 516
 const _WM_RBUTTONUP = 517
 const _WM_SETFONT = 48