diff --git a/CHANGELOG b/CHANGELOG
index 3318851..f7b8493 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Make Function#argumentNames work with named functions. Closes #9826. [Samuel Lebeau]
+
 * Add Object.isHash. [Tobie Langel]
 
 * Performance improvements to String#times. [Martin Ström]
diff --git a/src/base.js b/src/base.js
index 1ea0ba7..f73c9f9 100644
--- a/src/base.js
+++ b/src/base.js
@@ -154,7 +154,7 @@ Object.extend(Object, {
 
 Object.extend(Function.prototype, {
   argumentNames: function() {
-    var names = this.toString().match(/^[\s\(]*function\s*\((.*?)\)/)[1].split(",").invoke("strip");
+    var names = this.toString().match(/^[\s\(]*function[^(]*\((.*?)\)/)[1].split(",").invoke("strip");
     return names.length == 1 && !names[0] ? [] : names;
   },
   
diff --git a/test/unit/base.html b/test/unit/base.html
index 2941793..12a8d80 100644
--- a/test/unit/base.html
+++ b/test/unit/base.html
@@ -140,6 +140,13 @@
       assertEnumEqual(["one"], (function(one) {}).argumentNames());
       assertEnumEqual(["one", "two", "three"], (function(one, two, three) {}).argumentNames());
       assertEqual("$super", (function($super) {}).argumentNames().first());
+      
+      function named1() {};
+      assertEnumEqual([], named1.argumentNames());
+      function named2(one) {};
+      assertEnumEqual(["one"], named2.argumentNames());
+      function named3(one, two, three) {};
+      assertEnumEqual(["one", "two", "three"], named3.argumentNames());
     }},
     
     testFunctionBind: function() { with(this) {