diff --git a/src/js/select2/defaults.js b/src/js/select2/defaults.js
index 885feaca..ad4d224f 100644
--- a/src/js/select2/defaults.js
+++ b/src/js/select2/defaults.js
@@ -55,7 +55,7 @@ define([
   }
 
   Defaults.prototype.apply = function (options) {
-    options = $.extend({}, this.defaults, options);
+    options = $.extend(true, {}, this.defaults, options);
 
     if (options.dataAdapter == null) {
       if (options.ajax != null) {