diff --git a/Objective-J/OldBrowserCompatibility.js b/Objective-J/OldBrowserCompatibility.js
index cd3d30517..d4e43b937 100644
--- a/Objective-J/OldBrowserCompatibility.js
+++ b/Objective-J/OldBrowserCompatibility.js
@@ -115,3 +115,24 @@ if (!Array.prototype.indexOf)
         return -1;
     };
 }
+
+// ECMAScript 6 has added this. It is copied from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String
+if (!String.prototype.startsWith) {
+    String.prototype.startsWith = function(searchString, position){
+      position = position || 0;
+      return this.substr(position, searchString.length) === searchString;
+  };
+}
+
+// ECMAScript 6 has added this. It is copied from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String
+if (!String.prototype.endsWith) {
+  String.prototype.endsWith = function(searchString, position) {
+      var subjectString = this.toString();
+      if (typeof position !== 'number' || !isFinite(position) || Math.floor(position) !== position || position > subjectString.length) {
+        position = subjectString.length;
+      }
+      position -= searchString.length;
+      var lastIndex = subjectString.indexOf(searchString, position);
+      return lastIndex !== -1 && lastIndex === position;
+  };
+};
\ No newline at end of file