diff --git a/CHANGELOG b/CHANGELOG
index 5a2cccc..03df885 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,5 @@
+* Speed up Function#argumentNames. Avoid Enum dependency. (samleb, Tobie Langel)
+
 * Fix Event#element accessing inexistent tagName property (e.g. when element is a document). (kangax)
 
 * Amended failing Element#identify test.
diff --git a/src/base.js b/src/base.js
index 2d75f32..6120c41 100644
--- a/src/base.js
+++ b/src/base.js
@@ -159,7 +159,7 @@ Object.extend(Object, {
 
 Object.extend(Function.prototype, {
   argumentNames: function() {
-    var names = this.toString().match(/^[\s\(]*function[^(]*\((.*?)\)/)[1].split(",").invoke("strip");
+    var names = this.toString().match(/^[\s\(]*function[^(]*\((.*?)\)/)[1].split(/\s*,\s*/);
     return names.length == 1 && !names[0] ? [] : names;
   },