diff --git a/README.md b/README.md
index ac34c5e..c23f77e 100644
--- a/README.md
+++ b/README.md
@@ -121,7 +121,7 @@ type WinBoxPropType = {
   width?: string | number,
   fullscreen?: boolean, // a wrapper prop for fullscreen() method
 
-  onclose?: (force?: boolean) => boolean | undefined | void,
+  onclose?: (force: boolean) => boolean | undefined | void,
   onmove?: (x: number, y: number) => any,
   onresize?: (width: number, height: number) => any,
   onblur?: () => any,
diff --git a/dist/index.d.ts b/dist/index.d.ts
index 409df33..56741d8 100644
--- a/dist/index.d.ts
+++ b/dist/index.d.ts
@@ -40,10 +40,10 @@ export declare type WinBoxPropType = {
      *
      * see the following document for more detail about the argument and the return value.
      * @see https://github.com/nextapps-de/winbox
-     * @param force whether you should not abort the winbox to close.
+     * @param force Whether you should not abort the winbox to close. If this is true, you MUST return false, or some problems will happen.
      * @return noDefaultClose - true if the winbox does not need the default close process, for example, when it needs a confirmation to close instead of being closed suddenly.
      */
-    onclose?: (force?: boolean) => boolean | undefined | void;
+    onclose?: (force: boolean) => boolean | undefined | void;
     onmove?: (x: number, y: number) => any;
     onresize?: (width: number, height: number) => any;
     onblur?: () => any;
diff --git a/dist/index.js b/dist/index.js
index 3a3eed2..4a22876 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -139,7 +139,7 @@ var WinBox = /** @class */ (function (_super) {
                 throw 'duplicated window id';
             this.winBoxObj = new winbox_1.default(__assign(__assign({ width: 300, height: 200, top: 0, bottom: 0, left: 0, right: 0 }, this.props), { class: "".concat((_a = this.props.className) !== null && _a !== void 0 ? _a : ''), onclose: function (force) {
                     var _a, _b;
-                    if ((_b = (_a = _this.props).onclose) === null || _b === void 0 ? void 0 : _b.call(_a, force)) {
+                    if ((_b = (_a = _this.props).onclose) === null || _b === void 0 ? void 0 : _b.call(_a, force !== null && force !== void 0 ? force : false)) {
                         return true;
                     }
                     _this.handleClose(); // only when false, do close process.
diff --git a/package-lock.json b/package-lock.json
index 993f60e..3e41ab1 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "react-winbox",
-  "version": "1.4.1",
+  "version": "1.4.2",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "react-winbox",
-      "version": "1.4.1",
+      "version": "1.4.2",
       "license": "MIT",
       "dependencies": {
         "winbox": "^0.2.1"
diff --git a/package.json b/package.json
index 1d45333..6f618db 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "react-winbox",
-  "version": "1.4.1",
+  "version": "1.4.2",
   "description": "The React component for WinBox.js. Full Reactful props and state. A window manager for React",
   "private": false,
   "homepage": "https://github.com/rickonono3/react-winbox",
diff --git a/publish.sh b/publish.sh
new file mode 100755
index 0000000..e6c8528
--- /dev/null
+++ b/publish.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+yarn install
+npm install
+npm run build
+git add .
+git commit -m "publish from $(date +'%Y-%m-%d %H:%M:%S')"
+npm version patch
+npm publish
+git push