diff --git a/chrome/content/zotero/xpcom/utilities.js b/chrome/content/zotero/xpcom/utilities.js
index 6e0b66bc7..d425665cc 100644
--- a/chrome/content/zotero/xpcom/utilities.js
+++ b/chrome/content/zotero/xpcom/utilities.js
@@ -604,23 +604,19 @@ Zotero.Utilities = {
 	/**
 	 * Return new array with duplicate values removed
 	 *
-	 * From the JSLab Standard Library (JSL)
-	 * Copyright 2007 - 2009 Tavs Dokkedahl
-	 * Contact: http://www.jslab.dk/contact.php
+	 * From http://stackoverflow.com/a/1961068
 	 *
 	 * @param	{Array}		array
 	 * @return	{Array}
 	 */
 	"arrayUnique":function(arr) {
-		var a = [];
-		var l = arr.length;
-		for(var i=0; i<l; i++) {
-			for(var j=i+1; j<l; j++) {
-				// If this[i] is found later in the array
-				if (arr[i] === arr[j])
-					j = ++i;
+		var u = {}, a = [];
+		for (var i=0, l=arr.length; i<l; ++i){
+			if (u.hasOwnProperty(arr[i])) {
+				continue;
 			}
 			a.push(arr[i]);
+			u[arr[i]] = 1;
 		}
 		return a;
 	},