diff --git a/list_windows.go b/list_windows.go
index 36afb19..1c7a829 100644
--- a/list_windows.go
+++ b/list_windows.go
@@ -17,7 +17,7 @@ func listMultiple(text string, items []string, opts options) ([]string, error) {
 	return listDlg(text, items, true, opts)
 }
 
-func listDlg(text string, items []string, multiple bool, opts options) (out []string, err error) {
+func listDlg(text string, items []string, multiple bool, opts options) ([]string, error) {
 	if opts.title == nil {
 		opts.title = stringPtr("")
 	}
@@ -29,82 +29,12 @@ func listDlg(text string, items []string, multiple bool, opts options) (out []st
 	}
 
 	defer setup()()
-	font := getFont()
-	defer font.delete()
-	defWindowProc := defWindowProc.Addr()
-
-	var wnd, textCtl, listCtl uintptr
-	var okBtn, cancelBtn, extraBtn uintptr
-
-	layout := func(dpi dpi) {
-		hfont := font.forDPI(dpi)
-		sendMessage.Call(textCtl, 0x0030 /* WM_SETFONT */, hfont, 1)
-		sendMessage.Call(listCtl, 0x0030 /* WM_SETFONT */, hfont, 1)
-		sendMessage.Call(okBtn, 0x0030 /* WM_SETFONT */, hfont, 1)
-		sendMessage.Call(cancelBtn, 0x0030 /* WM_SETFONT */, hfont, 1)
-		sendMessage.Call(extraBtn, 0x0030 /* WM_SETFONT */, hfont, 1)
-		setWindowPos.Call(wnd, 0, 0, 0, dpi.scale(281), dpi.scale(281), 0x6)                             // SWP_NOZORDER|SWP_NOMOVE
-		setWindowPos.Call(textCtl, 0, dpi.scale(12), dpi.scale(10), dpi.scale(241), dpi.scale(16), 0x4)  // SWP_NOZORDER
-		setWindowPos.Call(listCtl, 0, dpi.scale(12), dpi.scale(30), dpi.scale(241), dpi.scale(164), 0x4) // SWP_NOZORDER
-		if extraBtn == 0 {
-			setWindowPos.Call(okBtn, 0, dpi.scale(95), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4)      // SWP_NOZORDER
-			setWindowPos.Call(cancelBtn, 0, dpi.scale(178), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4) // SWP_NOZORDER
-		} else {
-			setWindowPos.Call(okBtn, 0, dpi.scale(12), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4)      // SWP_NOZORDER
-			setWindowPos.Call(extraBtn, 0, dpi.scale(95), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4)   // SWP_NOZORDER
-			setWindowPos.Call(cancelBtn, 0, dpi.scale(178), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4) // SWP_NOZORDER
-		}
-	}
-
-	proc := func(wnd uintptr, msg uint32, wparam, lparam uintptr) uintptr {
-		switch msg {
-		case 0x0002: // WM_DESTROY
-			postQuitMessage.Call(0)
-
-		case 0x0010: // WM_CLOSE
-			err = ErrCanceled
-			destroyWindow.Call(wnd)
-
-		case 0x0111: // WM_COMMAND
-			switch wparam {
-			default:
-				return 1
-			case 1, 6: // IDOK, IDYES
-				if multiple {
-					if len, _, _ := sendMessage.Call(listCtl, 0x190 /* LB_GETSELCOUNT */, 0, 0); int32(len) >= 0 {
-						out = make([]string, len)
-						if len > 0 {
-							indices := make([]int32, len)
-							sendMessage.Call(listCtl, 0x191 /* LB_GETSELITEMS */, len, uintptr(unsafe.Pointer(&indices[0])))
-							for i, idx := range indices {
-								out[i] = items[idx]
-							}
-						}
-					}
-				} else {
-					if idx, _, _ := sendMessage.Call(listCtl, 0x188 /* LB_GETCURSEL */, 0, 0); int32(idx) >= 0 {
-						out = []string{items[idx]}
-					} else {
-						out = []string{}
-					}
-				}
-			case 2: // IDCANCEL
-				err = ErrCanceled
-			case 7: // IDNO
-				err = ErrExtraButton
-			}
-			destroyWindow.Call(wnd)
-
-		case 0x02e0: // WM_DPICHANGED
-			layout(dpi(uint32(wparam) >> 16))
-
-		default:
-			res, _, _ := syscall.Syscall6(defWindowProc, 4, wnd, uintptr(msg), wparam, lparam, 0, 0)
-			return res
-		}
-
-		return 0
+	wnd := &listWnd{
+		items:    items,
+		multiple: multiple,
+		font:     getFont(),
 	}
+	defer wnd.font.delete()
 
 	if opts.ctx != nil && opts.ctx.Err() != nil {
 		return nil, opts.ctx.Err()
@@ -115,56 +45,56 @@ func listDlg(text string, items []string, multiple bool, opts options) (out []st
 		return nil, err
 	}
 
-	cls, err := registerClass(instance, syscall.NewCallback(proc))
+	cls, err := registerClass(instance, syscall.NewCallback(listProc))
 	if cls == 0 {
 		return nil, err
 	}
 	defer unregisterClass.Call(cls, instance)
 
-	wnd, _, _ = createWindowEx.Call(0x10101, // WS_EX_CONTROLPARENT|WS_EX_WINDOWEDGE|WS_EX_DLGMODALFRAME
+	wnd.handle, _, _ = createWindowEx.Call(0x10101, // WS_EX_CONTROLPARENT|WS_EX_WINDOWEDGE|WS_EX_DLGMODALFRAME
 		cls, strptr(*opts.title),
 		0x84c80000, // WS_POPUPWINDOW|WS_CLIPSIBLINGS|WS_DLGFRAME
 		0x80000000, // CW_USEDEFAULT
 		0x80000000, // CW_USEDEFAULT
-		281, 281, 0, 0, instance, 0)
+		281, 281, 0, 0, instance, uintptr(unsafe.Pointer(wnd)))
 
-	textCtl, _, _ = createWindowEx.Call(0,
+	wnd.textCtl, _, _ = createWindowEx.Call(0,
 		strptr("STATIC"), strptr(text),
 		0x5002e080, // WS_CHILD|WS_VISIBLE|WS_GROUP|SS_WORDELLIPSIS|SS_EDITCONTROL|SS_NOPREFIX
-		12, 10, 241, 16, wnd, 0, instance, 0)
+		12, 10, 241, 16, wnd.handle, 0, instance, 0)
 
 	var flags uintptr = 0x50320000 // WS_CHILD|WS_VISIBLE|WS_VSCROLL|WS_GROUP|WS_TABSTOP
 	if multiple {
 		flags |= 0x0800 // LBS_EXTENDEDSEL
 	}
-	listCtl, _, _ = createWindowEx.Call(0x200, // WS_EX_CLIENTEDGE
+	wnd.listCtl, _, _ = createWindowEx.Call(0x200, // WS_EX_CLIENTEDGE
 		strptr("LISTBOX"), strptr(opts.entryText),
 		flags,
-		12, 30, 241, 164, wnd, 0, instance, 0)
+		12, 30, 241, 164, wnd.handle, 0, instance, 0)
 
-	okBtn, _, _ = createWindowEx.Call(0,
+	wnd.okBtn, _, _ = createWindowEx.Call(0,
 		strptr("BUTTON"), strptr(*opts.okLabel),
 		0x50030001, // WS_CHILD|WS_VISIBLE|WS_GROUP|WS_TABSTOP|BS_DEFPUSHBUTTON
-		12, 206, 75, 24, wnd, 1 /* IDOK */, instance, 0)
-	cancelBtn, _, _ = createWindowEx.Call(0,
+		12, 206, 75, 24, wnd.handle, 1 /* IDOK */, instance, 0)
+	wnd.cancelBtn, _, _ = createWindowEx.Call(0,
 		strptr("BUTTON"), strptr(*opts.cancelLabel),
 		0x50010000, // WS_CHILD|WS_VISIBLE|WS_GROUP|WS_TABSTOP
-		12, 206, 75, 24, wnd, 2 /* IDCANCEL */, instance, 0)
+		12, 206, 75, 24, wnd.handle, 2 /* IDCANCEL */, instance, 0)
 	if opts.extraButton != nil {
-		extraBtn, _, _ = createWindowEx.Call(0,
+		wnd.extraBtn, _, _ = createWindowEx.Call(0,
 			strptr("BUTTON"), strptr(*opts.extraButton),
 			0x50010000, // WS_CHILD|WS_VISIBLE|WS_GROUP|WS_TABSTOP
-			12, 206, 75, 24, wnd, 7 /* IDNO */, instance, 0)
+			12, 206, 75, 24, wnd.handle, 7 /* IDNO */, instance, 0)
 	}
 
 	for _, item := range items {
-		sendMessage.Call(listCtl, 0x180 /* LB_ADDSTRING */, 0, strptr(item))
+		sendMessage.Call(wnd.listCtl, 0x180 /* LB_ADDSTRING */, 0, strptr(item))
 	}
 
-	layout(getDPI(wnd))
-	centerWindow(wnd)
-	setFocus.Call(listCtl)
-	showWindow.Call(wnd, 1 /* SW_SHOWNORMAL */, 0)
+	wnd.layout(getDPI(wnd.handle))
+	centerWindow(wnd.handle)
+	setFocus.Call(wnd.listCtl)
+	showWindow.Call(wnd.handle, 1 /* SW_SHOWNORMAL */, 0)
 
 	if opts.ctx != nil {
 		wait := make(chan struct{})
@@ -172,20 +102,112 @@ func listDlg(text string, items []string, multiple bool, opts options) (out []st
 		go func() {
 			select {
 			case <-opts.ctx.Done():
-				sendMessage.Call(wnd, 0x0112 /* WM_SYSCOMMAND */, 0xf060 /* SC_CLOSE */, 0)
+				sendMessage.Call(wnd.handle, 0x0112 /* WM_SYSCOMMAND */, 0xf060 /* SC_CLOSE */, 0)
 			case <-wait:
 			}
 		}()
 	}
 
-	// set default values
-	out, err = nil, nil
-
-	if err := messageLoop(wnd); err != nil {
+	if err := messageLoop(wnd.handle); err != nil {
 		return nil, err
 	}
 	if opts.ctx != nil && opts.ctx.Err() != nil {
 		return nil, opts.ctx.Err()
 	}
-	return out, err
+	return wnd.out, wnd.err
+}
+
+type listWnd struct {
+	handle    uintptr
+	textCtl   uintptr
+	listCtl   uintptr
+	okBtn     uintptr
+	cancelBtn uintptr
+	extraBtn  uintptr
+	multiple  bool
+	items     []string
+	out       []string
+	err       error
+	font      font
+}
+
+func (wnd *listWnd) layout(dpi dpi) {
+	font := wnd.font.forDPI(dpi)
+	sendMessage.Call(wnd.textCtl, 0x0030 /* WM_SETFONT */, font, 1)
+	sendMessage.Call(wnd.listCtl, 0x0030 /* WM_SETFONT */, font, 1)
+	sendMessage.Call(wnd.okBtn, 0x0030 /* WM_SETFONT */, font, 1)
+	sendMessage.Call(wnd.cancelBtn, 0x0030 /* WM_SETFONT */, font, 1)
+	sendMessage.Call(wnd.extraBtn, 0x0030 /* WM_SETFONT */, font, 1)
+	setWindowPos.Call(wnd.handle, 0, 0, 0, dpi.scale(281), dpi.scale(281), 0x6)                          // SWP_NOZORDER|SWP_NOMOVE
+	setWindowPos.Call(wnd.textCtl, 0, dpi.scale(12), dpi.scale(10), dpi.scale(241), dpi.scale(16), 0x4)  // SWP_NOZORDER
+	setWindowPos.Call(wnd.listCtl, 0, dpi.scale(12), dpi.scale(30), dpi.scale(241), dpi.scale(164), 0x4) // SWP_NOZORDER
+	if wnd.extraBtn == 0 {
+		setWindowPos.Call(wnd.okBtn, 0, dpi.scale(95), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4)      // SWP_NOZORDER
+		setWindowPos.Call(wnd.cancelBtn, 0, dpi.scale(178), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4) // SWP_NOZORDER
+	} else {
+		setWindowPos.Call(wnd.okBtn, 0, dpi.scale(12), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4)      // SWP_NOZORDER
+		setWindowPos.Call(wnd.extraBtn, 0, dpi.scale(95), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4)   // SWP_NOZORDER
+		setWindowPos.Call(wnd.cancelBtn, 0, dpi.scale(178), dpi.scale(206), dpi.scale(75), dpi.scale(24), 0x4) // SWP_NOZORDER
+	}
+}
+
+func listProc(hwnd uintptr, msg uint32, wparam uintptr, lparam *unsafe.Pointer) uintptr {
+	var wnd *listWnd
+	switch msg {
+	case 0x0081: // WM_NCCREATE
+		saveBackRef(hwnd, *lparam)
+		wnd = (*listWnd)(*lparam)
+	case 0x0082: // WM_NCDESTROY
+		deleteBackRef(hwnd)
+	default:
+		wnd = (*listWnd)(loadBackRef(hwnd))
+	}
+
+	switch msg {
+	case 0x0002: // WM_DESTROY
+		postQuitMessage.Call(0)
+
+	case 0x0010: // WM_CLOSE
+		wnd.err = ErrCanceled
+		destroyWindow.Call(hwnd)
+
+	case 0x0111: // WM_COMMAND
+		switch wparam {
+		default:
+			return 1
+		case 1, 6: // IDOK, IDYES
+			if wnd.multiple {
+				if len, _, _ := sendMessage.Call(wnd.listCtl, 0x190 /* LB_GETSELCOUNT */, 0, 0); int32(len) >= 0 {
+					wnd.out = make([]string, len)
+					if len > 0 {
+						indices := make([]int32, len)
+						sendMessage.Call(wnd.listCtl, 0x191 /* LB_GETSELITEMS */, len, uintptr(unsafe.Pointer(&indices[0])))
+						for i, idx := range indices {
+							wnd.out[i] = wnd.items[idx]
+						}
+					}
+				}
+			} else {
+				if idx, _, _ := sendMessage.Call(wnd.listCtl, 0x188 /* LB_GETCURSEL */, 0, 0); int32(idx) >= 0 {
+					wnd.out = []string{wnd.items[idx]}
+				} else {
+					wnd.out = []string{}
+				}
+			}
+		case 2: // IDCANCEL
+			wnd.err = ErrCanceled
+		case 7: // IDNO
+			wnd.err = ErrExtraButton
+		}
+		destroyWindow.Call(hwnd)
+
+	case 0x02e0: // WM_DPICHANGED
+		wnd.layout(dpi(uint32(wparam) >> 16))
+
+	default:
+		res, _, _ := syscall.Syscall6(defWindowProc.Addr(), 4, hwnd, uintptr(msg), wparam, uintptr(unsafe.Pointer(lparam)), 0, 0)
+		return res
+	}
+
+	return 0
 }