diff --git a/lib/utils/prototypes.js b/lib/utils/prototypes.js
index 795044b..014449e 100644
--- a/lib/utils/prototypes.js
+++ b/lib/utils/prototypes.js
@@ -68,9 +68,6 @@ Object.defineProperty(Array.prototype, 'extend', {
 })
 
 Object.defineProperty(Object, 'isObject', {
-  configurable: true,
-  enumerable: false,
-  writable: true,
   value: function (obj) {
     return (obj != null && typeof obj === 'object' &&
     Object.prototype.toString.call(obj) === '[object Object]')