diff --git a/dist/dush.common.js b/dist/dush.common.js
index 89987bc..7f8e79f 100644
--- a/dist/dush.common.js
+++ b/dist/dush.common.js
@@ -140,7 +140,7 @@ function dush () {
       }
 
       var fn = once ? func : handler;
-      fn.sourceString = handler.toString();
+      fn.__sourceString = handler.toString();
 
       e.push(fn);
       return app
@@ -221,7 +221,7 @@ function dush () {
     off: function off (name, handler) {
       if (handler && app._allEvents[name]) {
         var fnStr = handler.toString();
-        app._allEvents[name] = app._allEvents[name].filter(function (func) { return func.sourceString !== fnStr; });
+        app._allEvents[name] = app._allEvents[name].filter(function (func) { return func.__sourceString !== fnStr; });
       } else if (name) {
         app._allEvents[name] = [];
       } else {
diff --git a/dist/dush.es.js b/dist/dush.es.js
index b496676..0ab240d 100644
--- a/dist/dush.es.js
+++ b/dist/dush.es.js
@@ -138,7 +138,7 @@ function dush () {
       }
 
       var fn = once ? func : handler;
-      fn.sourceString = handler.toString();
+      fn.__sourceString = handler.toString();
 
       e.push(fn);
       return app
@@ -219,7 +219,7 @@ function dush () {
     off: function off (name, handler) {
       if (handler && app._allEvents[name]) {
         var fnStr = handler.toString();
-        app._allEvents[name] = app._allEvents[name].filter(function (func) { return func.sourceString !== fnStr; });
+        app._allEvents[name] = app._allEvents[name].filter(function (func) { return func.__sourceString !== fnStr; });
       } else if (name) {
         app._allEvents[name] = [];
       } else {
diff --git a/dist/dush.umd.js b/dist/dush.umd.js
index 948b6b7..a78837e 100644
--- a/dist/dush.umd.js
+++ b/dist/dush.umd.js
@@ -1,2 +1,2 @@
-!function(n,e){"object"==typeof exports&&"undefined"!=typeof module?module.exports=e():"function"==typeof define&&define.amd?define(e):n.dush=e()}(this,function(){function n(){var n=Object.create(null),e={_allEvents:n,use:function(n){return n(e)||e},on:function(n,t,l){function r(){r.called||(e.off(n,r),t.apply(t,arguments),r.called=!0)}var u=e._allEvents[n]||(e._allEvents[n]=[]),o=l?r:t;return o.sourceString=t.toString(),u.push(o),e},once:function(n,t){return e.on(n,t,!0),e},off:function(n,t){if(t&&e._allEvents[n]){var l=t.toString();e._allEvents[n]=e._allEvents[n].filter(function(n){return n.sourceString!==l})}else n?e._allEvents[n]=[]:e._allEvents=Object.create(null);return e},emit:function(n){if("*"!==n){var t=[].slice.call(arguments);(e._allEvents[n]||[]).map(function(n){n.apply(n,t.slice(1))}),(e._allEvents["*"]||[]).map(function(n){n.apply(n,t)})}return e}};return e}return n});
+!function(n,e){"object"==typeof exports&&"undefined"!=typeof module?module.exports=e():"function"==typeof define&&define.amd?define(e):n.dush=e()}(this,function(){function n(){var n=Object.create(null),e={_allEvents:n,use:function(n){return n(e)||e},on:function(n,t,l){function r(){r.called||(e.off(n,r),t.apply(t,arguments),r.called=!0)}var u=e._allEvents[n]||(e._allEvents[n]=[]),o=l?r:t;return o.__sourceString=t.toString(),u.push(o),e},once:function(n,t){return e.on(n,t,!0),e},off:function(n,t){if(t&&e._allEvents[n]){var l=t.toString();e._allEvents[n]=e._allEvents[n].filter(function(n){return n.__sourceString!==l})}else n?e._allEvents[n]=[]:e._allEvents=Object.create(null);return e},emit:function(n){if("*"!==n){var t=[].slice.call(arguments);(e._allEvents[n]||[]).map(function(n){n.apply(n,t.slice(1))}),(e._allEvents["*"]||[]).map(function(n){n.apply(n,t)})}return e}};return e}return n});
 //# sourceMappingURL=dush.umd.js.map
diff --git a/dist/dush.umd.js.gz b/dist/dush.umd.js.gz
index b7c7aac..f59bd13 100644
Binary files a/dist/dush.umd.js.gz and b/dist/dush.umd.js.gz differ
diff --git a/dist/dush.umd.js.map b/dist/dush.umd.js.map
index 402d85e..30f98e1 100644
--- a/dist/dush.umd.js.map
+++ b/dist/dush.umd.js.map
@@ -1 +1 @@
-{"version":3,"file":"dush.umd.js","sources":["../src/index.js"],"sourcesContent":["/*!\n * dush <https://github.com/tunnckoCore/dush>\n *\n * Copyright (c) Charlike Mike Reagent <@tunnckoCore> (https://i.am.charlike.online)\n * Released under the MIT license.\n */\n\n'use strict'\n\n/**\n * > A constructor function that returns an object\n * with a few methods.\n *\n * See [JSBin Example](http://jsbin.com/mepemeluhi/edit?js,console).\n *\n * **Example**\n *\n * ```js\n * const dush = require('dush')\n * const emitter = dush()\n *\n * console.log(emitter._allEvents) // => {}\n * console.log(emitter.on) // => Function\n * console.log(emitter.once) // => Function\n * console.log(emitter.off) // => Function\n * console.log(emitter.emit) // => Function\n * ```\n *\n * @name   dush()\n * @return {Object} methods\n * @api public\n */\n\nexport default function dush () {\n  let _allEvents = Object.create(null)\n  const app = {\n    /**\n     * > An listeners map of all registered events\n     * and their listeners. A key/value store, where 1) value\n     * is an array of event listeners for the key and 2) key\n     * is the name of the event.\n     *\n     * See [JSBin Example](http://jsbin.com/fakajazafu/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     *\n     * emitter.on('foo', () => {})\n     * emitter.on('foo', () => {})\n     * emitter.on('bar', () => {})\n     *\n     * console.log(emitter._allEvents)\n     * // => { foo: [Function, Function], bar: [Functon] }\n     *\n     * console.log(emitter._allEvents.foo.length) // => 2\n     * console.log(emitter._allEvents.bar.length) // => 1\n     * ```\n     *\n     * @name  ._allEvents\n     * @type {Object} `_allEvents` a key/value store of all events and their listeners\n     * @api public\n     */\n\n    _allEvents,\n\n    /**\n     * > Invokes `plugin` function immediately, which is passed\n     * with `app` instance. You can use it for adding more methods\n     * or properties to the instance. Useful if you want to make\n     * dush to work with DOM for example.\n     *\n     * ```js\n     * const app = dush()\n     *\n     * app.on('hi', (str) => {\n     *   console.log(str) // => 'Hello World!!'\n     * })\n     *\n     * app.use((app) => {\n     *   app.foo = 'bar'\n     *   app.hello = (place) => app.emit('hi', `Hello ${place}!!`)\n     * })\n     *\n     * console.log(app.foo) // => 'bar'\n     * app.hello('World')\n     * ```\n     *\n     * @name   .use\n     * @param  {Function} `plugin` A function passed with `(app)` signature\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    use (plugin) {\n      const ret = plugin(app)\n      return ret || app\n    },\n\n    /**\n     * > Add `handler` for `name` event.\n     *\n     * See [JSBin Example](http://jsbin.com/xeketuruto/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     *\n     * emitter\n     *   .on('hi', (place) => {\n     *     console.log(`hello ${place}!`) // => 'hello world!'\n     *   })\n     *   .on('hi', (place) => {\n     *     console.log(`hi ${place}, yeah!`) // => 'hi world, yeah!'\n     *   })\n     *\n     * emitter.emit('hi', 'world')\n     * ```\n     *\n     * @name   .on\n     * @param  {String} `name` Type of event to listen for, or `'*'` for all events\n     * @param  {Function} `handler` Function to call in response to given event\n     * @param  {Boolean} `once` Make `handler` be called only once,\n     *                          the `.once` method use this internally\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    on (name, handler, once) {\n      let e = app._allEvents[name] || (app._allEvents[name] = [])\n\n      function func () {\n        if (!func.called) {\n          app.off(name, func)\n          handler.apply(handler, arguments)\n          func.called = true\n        }\n      }\n\n      var fn = once ? func : handler\n      fn.sourceString = handler.toString()\n\n      e.push(fn)\n      return app\n    },\n\n    /**\n     * > Add `handler` for `name` event that\n     * will be called only one time.\n     *\n     * See [JSBin Example](http://jsbin.com/teculorima/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     * let called = 0\n     *\n     * emitter.once('foo', () => {\n     *   console.log('called only once')\n     *   called++\n     * })\n     *\n     * emitter\n     *   .emit('foo', 111)\n     *   .emit('foo', 222)\n     *   .emit('foo', 333)\n     *\n     * console.log(called) // => 1\n     * ```\n     *\n     * @name   .once\n     * @param  {String} `name` Type of event to listen for, or `'*'` for all events\n     * @param  {Function} `handler` Function to call in response to given event\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    once (name, handler) {\n      app.on(name, handler, true)\n      return app\n    },\n\n    /**\n     * > Remove `handler` for `name` event. If `handler` not\n     * passed will remove **all** listeners for that `name` event.\n     *\n     * See [JSBin Example](http://jsbin.com/nujucoquvi/3/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     *\n     * const handler = () => {\n     *   console.log('not called')\n     * }\n     *\n     * emitter.on('foo', handler)\n     * emitter.off('foo', handler)\n     *\n     * emitter.on('foo', (abc) => {\n     *   console.log('called', abc) // => 'called 123'\n     * })\n     * emitter.emit('foo', 123)\n     *\n     * // or removing all listeners of `foo`\n     * emitter.off('foo')\n     * emitter.emit('foo')\n     * ```\n     *\n     * @name   .off\n     * @param  {String} `name` Type of event to listen for, or `'*'` for all events\n     * @param  {Function} `handler` Function to call in response to given event\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    off (name, handler) {\n      if (handler && app._allEvents[name]) {\n        const fnStr = handler.toString()\n        app._allEvents[name] = app._allEvents[name].filter((func) => func.sourceString !== fnStr)\n      } else if (name) {\n        app._allEvents[name] = []\n      } else {\n        app._allEvents = Object.create(null)\n      }\n\n      return app\n    },\n\n    /**\n     * > Invoke all handlers for given `name` event.\n     * If present, `'*'` listeners are invoked too with `(type, ...rest)` signature,\n     * where the `type` argument is a string representing the name of the\n     * called event; and all of the rest arguments.\n     *\n     * See [JSBin Example](http://jsbin.com/muqujavolu/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     *\n     * emitter.on('foo', (a, b, c) => {\n     *   console.log(`${a}, ${b}, ${c}`) // => 1, 2, 3\n     * })\n     *\n     * emitter.on('*', (name, a, b, c) => {\n     *   console.log(`name is: ${name}`)\n     *   console.log(`rest args are: ${a}, ${b}, ${c}`)\n     * })\n     *\n     * emitter.emit('foo', 1, 2, 3)\n     * emitter.emit('bar', 555)\n     * ```\n     *\n     * @name   .emit\n     * @param  {String} `name` The name of the event to invoke\n     * @param  {any} `args` Any number of arguments of any type of value, passed to each listener\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    emit (name) {\n      if (name !== '*') {\n        var args = [].slice.call(arguments);\n        (app._allEvents[name] || []).map((handler) => { handler.apply(handler, args.slice(1)) });\n        (app._allEvents['*'] || []).map((handler) => { handler.apply(handler, args) })\n      }\n\n      return app\n    }\n  }\n\n  return app\n}\n"],"names":["dush","let","_allEvents","Object","create","app","use","plugin","on","name","handler","once","func","called","off","apply","arguments","e","fn","sourceString","toString","push","const","fnStr","filter","emit","args","slice","call","map"],"mappings":"mKAiCA,QAAwBA,KACtBC,GAAIC,GAAaC,OAAOC,OAAO,MACzBC,GA8BJH,WAAAA,EA8BAI,aAAKC,GAEH,MADYA,GAAOF,IACLA,GAiChBG,YAAIC,EAAMC,EAASC,GAGjB,QAASC,KACFA,EAAKC,SACRR,EAAIS,IAAIL,EAAMG,GACdF,EAAQK,MAAML,EAASM,WACvBJ,EAAKC,QAAS,GANlBZ,GAAIgB,GAAIZ,EAAIH,WAAWO,KAAUJ,EAAIH,WAAWO,OAU5CS,EAAKP,EAAOC,EAAOF,CAIvB,OAHAQ,GAAGC,aAAeT,EAAQU,WAE1BH,EAAEI,KAAKH,GACAb,GAmCTM,cAAMF,EAAMC,GAEV,MADAL,GAAIG,GAAGC,EAAMC,GAAS,GACfL,GAsCTS,aAAKL,EAAMC,GACT,GAAIA,GAAWL,EAAIH,WAAWO,GAAO,CACnCa,GAAMC,GAAQb,EAAQU,UACtBf,GAAIH,WAAWO,GAAQJ,EAAIH,WAAWO,GAAMe,OAAO,SAACZ,SAASA,GAAKO,eAAiBI,QAC1Ed,GACTJ,EAAIH,WAAWO,MAEfJ,EAAIH,WAAaC,OAAOC,OAAO,KAGjC,OAAOC,IAoCToB,cAAMhB,GACJ,GAAa,MAATA,EAAc,CAChB,GAAIiB,MAAUC,MAAMC,KAAKZ,YACxBX,EAAIH,WAAWO,QAAaoB,IAAI,SAACnB,GAAcA,EAAQK,MAAML,EAASgB,EAAKC,MAAM,OACjFtB,EAAIH,WAAW,UAAY2B,IAAI,SAACnB,GAAcA,EAAQK,MAAML,EAASgB,KAGxE,MAAOrB,IAIX,OAAOA"}
\ No newline at end of file
+{"version":3,"file":"dush.umd.js","sources":["../src/index.js"],"sourcesContent":["/*!\n * dush <https://github.com/tunnckoCore/dush>\n *\n * Copyright (c) Charlike Mike Reagent <@tunnckoCore> (https://i.am.charlike.online)\n * Released under the MIT license.\n */\n\n'use strict'\n\n/**\n * > A constructor function that returns an object\n * with a few methods.\n *\n * See [JSBin Example](http://jsbin.com/mepemeluhi/edit?js,console).\n *\n * **Example**\n *\n * ```js\n * const dush = require('dush')\n * const emitter = dush()\n *\n * console.log(emitter._allEvents) // => {}\n * console.log(emitter.on) // => Function\n * console.log(emitter.once) // => Function\n * console.log(emitter.off) // => Function\n * console.log(emitter.emit) // => Function\n * ```\n *\n * @name   dush()\n * @return {Object} methods\n * @api public\n */\n\nexport default function dush () {\n  let _allEvents = Object.create(null)\n  const app = {\n    /**\n     * > An listeners map of all registered events\n     * and their listeners. A key/value store, where 1) value\n     * is an array of event listeners for the key and 2) key\n     * is the name of the event.\n     *\n     * See [JSBin Example](http://jsbin.com/fakajazafu/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     *\n     * emitter.on('foo', () => {})\n     * emitter.on('foo', () => {})\n     * emitter.on('bar', () => {})\n     *\n     * console.log(emitter._allEvents)\n     * // => { foo: [Function, Function], bar: [Functon] }\n     *\n     * console.log(emitter._allEvents.foo.length) // => 2\n     * console.log(emitter._allEvents.bar.length) // => 1\n     * ```\n     *\n     * @name  ._allEvents\n     * @type {Object} `_allEvents` a key/value store of all events and their listeners\n     * @api public\n     */\n\n    _allEvents,\n\n    /**\n     * > Invokes `plugin` function immediately, which is passed\n     * with `app` instance. You can use it for adding more methods\n     * or properties to the instance. Useful if you want to make\n     * dush to work with DOM for example.\n     *\n     * ```js\n     * const app = dush()\n     *\n     * app.on('hi', (str) => {\n     *   console.log(str) // => 'Hello World!!'\n     * })\n     *\n     * app.use((app) => {\n     *   app.foo = 'bar'\n     *   app.hello = (place) => app.emit('hi', `Hello ${place}!!`)\n     * })\n     *\n     * console.log(app.foo) // => 'bar'\n     * app.hello('World')\n     * ```\n     *\n     * @name   .use\n     * @param  {Function} `plugin` A function passed with `(app)` signature\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    use (plugin) {\n      const ret = plugin(app)\n      return ret || app\n    },\n\n    /**\n     * > Add `handler` for `name` event.\n     *\n     * See [JSBin Example](http://jsbin.com/xeketuruto/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     *\n     * emitter\n     *   .on('hi', (place) => {\n     *     console.log(`hello ${place}!`) // => 'hello world!'\n     *   })\n     *   .on('hi', (place) => {\n     *     console.log(`hi ${place}, yeah!`) // => 'hi world, yeah!'\n     *   })\n     *\n     * emitter.emit('hi', 'world')\n     * ```\n     *\n     * @name   .on\n     * @param  {String} `name` Type of event to listen for, or `'*'` for all events\n     * @param  {Function} `handler` Function to call in response to given event\n     * @param  {Boolean} `once` Make `handler` be called only once,\n     *                          the `.once` method use this internally\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    on (name, handler, once) {\n      let e = app._allEvents[name] || (app._allEvents[name] = [])\n\n      function func () {\n        if (!func.called) {\n          app.off(name, func)\n          handler.apply(handler, arguments)\n          func.called = true\n        }\n      }\n\n      var fn = once ? func : handler\n      fn.__sourceString = handler.toString()\n\n      e.push(fn)\n      return app\n    },\n\n    /**\n     * > Add `handler` for `name` event that\n     * will be called only one time.\n     *\n     * See [JSBin Example](http://jsbin.com/teculorima/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     * let called = 0\n     *\n     * emitter.once('foo', () => {\n     *   console.log('called only once')\n     *   called++\n     * })\n     *\n     * emitter\n     *   .emit('foo', 111)\n     *   .emit('foo', 222)\n     *   .emit('foo', 333)\n     *\n     * console.log(called) // => 1\n     * ```\n     *\n     * @name   .once\n     * @param  {String} `name` Type of event to listen for, or `'*'` for all events\n     * @param  {Function} `handler` Function to call in response to given event\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    once (name, handler) {\n      app.on(name, handler, true)\n      return app\n    },\n\n    /**\n     * > Remove `handler` for `name` event. If `handler` not\n     * passed will remove **all** listeners for that `name` event.\n     *\n     * See [JSBin Example](http://jsbin.com/nujucoquvi/3/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     *\n     * const handler = () => {\n     *   console.log('not called')\n     * }\n     *\n     * emitter.on('foo', handler)\n     * emitter.off('foo', handler)\n     *\n     * emitter.on('foo', (abc) => {\n     *   console.log('called', abc) // => 'called 123'\n     * })\n     * emitter.emit('foo', 123)\n     *\n     * // or removing all listeners of `foo`\n     * emitter.off('foo')\n     * emitter.emit('foo')\n     * ```\n     *\n     * @name   .off\n     * @param  {String} `name` Type of event to listen for, or `'*'` for all events\n     * @param  {Function} `handler` Function to call in response to given event\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    off (name, handler) {\n      if (handler && app._allEvents[name]) {\n        const fnStr = handler.toString()\n        app._allEvents[name] = app._allEvents[name].filter((func) => func.__sourceString !== fnStr)\n      } else if (name) {\n        app._allEvents[name] = []\n      } else {\n        app._allEvents = Object.create(null)\n      }\n\n      return app\n    },\n\n    /**\n     * > Invoke all handlers for given `name` event.\n     * If present, `'*'` listeners are invoked too with `(type, ...rest)` signature,\n     * where the `type` argument is a string representing the name of the\n     * called event; and all of the rest arguments.\n     *\n     * See [JSBin Example](http://jsbin.com/muqujavolu/edit?js,console).\n     *\n     * **Example**\n     *\n     * ```js\n     * const emitter = dush()\n     *\n     * emitter.on('foo', (a, b, c) => {\n     *   console.log(`${a}, ${b}, ${c}`) // => 1, 2, 3\n     * })\n     *\n     * emitter.on('*', (name, a, b, c) => {\n     *   console.log(`name is: ${name}`)\n     *   console.log(`rest args are: ${a}, ${b}, ${c}`)\n     * })\n     *\n     * emitter.emit('foo', 1, 2, 3)\n     * emitter.emit('bar', 555)\n     * ```\n     *\n     * @name   .emit\n     * @param  {String} `name` The name of the event to invoke\n     * @param  {any} `args` Any number of arguments of any type of value, passed to each listener\n     * @return {Object} The `dush` instance for chaining\n     * @api public\n     */\n\n    emit (name) {\n      if (name !== '*') {\n        var args = [].slice.call(arguments);\n        (app._allEvents[name] || []).map((handler) => { handler.apply(handler, args.slice(1)) });\n        (app._allEvents['*'] || []).map((handler) => { handler.apply(handler, args) })\n      }\n\n      return app\n    }\n  }\n\n  return app\n}\n"],"names":["dush","let","_allEvents","Object","create","app","use","plugin","on","name","handler","once","func","called","off","apply","arguments","e","fn","__sourceString","toString","push","const","fnStr","filter","emit","args","slice","call","map"],"mappings":"mKAiCA,QAAwBA,KACtBC,GAAIC,GAAaC,OAAOC,OAAO,MACzBC,GA8BJH,WAAAA,EA8BAI,aAAKC,GAEH,MADYA,GAAOF,IACLA,GAiChBG,YAAIC,EAAMC,EAASC,GAGjB,QAASC,KACFA,EAAKC,SACRR,EAAIS,IAAIL,EAAMG,GACdF,EAAQK,MAAML,EAASM,WACvBJ,EAAKC,QAAS,GANlBZ,GAAIgB,GAAIZ,EAAIH,WAAWO,KAAUJ,EAAIH,WAAWO,OAU5CS,EAAKP,EAAOC,EAAOF,CAIvB,OAHAQ,GAAGC,eAAiBT,EAAQU,WAE5BH,EAAEI,KAAKH,GACAb,GAmCTM,cAAMF,EAAMC,GAEV,MADAL,GAAIG,GAAGC,EAAMC,GAAS,GACfL,GAsCTS,aAAKL,EAAMC,GACT,GAAIA,GAAWL,EAAIH,WAAWO,GAAO,CACnCa,GAAMC,GAAQb,EAAQU,UACtBf,GAAIH,WAAWO,GAAQJ,EAAIH,WAAWO,GAAMe,OAAO,SAACZ,SAASA,GAAKO,iBAAmBI,QAC5Ed,GACTJ,EAAIH,WAAWO,MAEfJ,EAAIH,WAAaC,OAAOC,OAAO,KAGjC,OAAOC,IAoCToB,cAAMhB,GACJ,GAAa,MAATA,EAAc,CAChB,GAAIiB,MAAUC,MAAMC,KAAKZ,YACxBX,EAAIH,WAAWO,QAAaoB,IAAI,SAACnB,GAAcA,EAAQK,MAAML,EAASgB,EAAKC,MAAM,OACjFtB,EAAIH,WAAW,UAAY2B,IAAI,SAACnB,GAAcA,EAAQK,MAAML,EAASgB,KAGxE,MAAOrB,IAIX,OAAOA"}
\ No newline at end of file
diff --git a/src/index.js b/src/index.js
index ca11778..8c9dcdd 100644
--- a/src/index.js
+++ b/src/index.js
@@ -140,7 +140,7 @@ export default function dush () {
       }
 
       var fn = once ? func : handler
-      fn.sourceString = handler.toString()
+      fn.__sourceString = handler.toString()
 
       e.push(fn)
       return app
@@ -221,7 +221,7 @@ export default function dush () {
     off (name, handler) {
       if (handler && app._allEvents[name]) {
         const fnStr = handler.toString()
-        app._allEvents[name] = app._allEvents[name].filter((func) => func.sourceString !== fnStr)
+        app._allEvents[name] = app._allEvents[name].filter((func) => func.__sourceString !== fnStr)
       } else if (name) {
         app._allEvents[name] = []
       } else {