diff --git a/lib/class.js b/lib/class.js
index 5f776c9..07591a7 100644
--- a/lib/class.js
+++ b/lib/class.js
@@ -87,12 +87,9 @@ var extend = ( function( extending )
             base      = args.pop() || Class,
             prototype = new base();
 
-        // copy the given properties into the new prototype
-        var result_data = {
-            abstractMethods: ( base.abstractMethods || [] ).slice()
-        };
+        var properties       = {},
+            abstract_methods = ( base.abstractMethods || [] ).slice();
 
-        var properties = {};
         util.propCopy( props, prototype, {
             each: function( name, value )
             {
@@ -117,7 +114,7 @@ var extend = ( function( extending )
 
                 if ( ( pre === undefined ) && is_abstract  )
                 {
-                    result_data.abstractMethods.push( name );
+                    abstract_methods.push( name );
                 }
 
                 this.performDefault( name, func, is_abstract );
@@ -126,20 +123,20 @@ var extend = ( function( extending )
             methodOverride: function( name, pre, func )
             {
                 return util.overrideMethod(
-                    name, pre, func, result_data.abstractMethods
+                    name, pre, func, abstract_methods
                 );
             },
         } );
 
-        result_data.abstractMethods = util.arrayShrink( result_data.abstractMethods );
+        abstract_methods = util.arrayShrink( abstract_methods );
 
         // reference to the parent prototype (for more experienced users)
         prototype.parent = base.prototype;
 
         // set up the new class
-        var new_class = create_ctor( result_data );
+        var new_class = create_ctor( abstract_methods );
 
-        setup_props( new_class, result_data );
+        setup_props( new_class, abstract_methods );
         attach_prop_init( prototype, properties );
 
         new_class.prototype   = prototype;
@@ -162,14 +159,14 @@ var extend = ( function( extending )
      * This constructor will call the __constructor method for concrete classes
      * and throw an exception for abstract classes (to prevent instantiation).
      *
-     * @param  {Object}  result_data  data from property copy operation
+     * @param  {Array.<string>}  abstract_methods  list of abstract methods
      *
      * @return  {Function}  constructor
      */
-    function create_ctor( result_data, properties )
+    function create_ctor( abstract_methods )
     {
         // concrete class
-        if ( result_data.abstractMethods.length === 0 )
+        if ( abstract_methods.length === 0 )
         {
             return function()
             {
@@ -200,14 +197,14 @@ var extend = ( function( extending )
 /**
  * Sets up common properties for the provided function (class)
  *
- * @param  {Function}  func        function (class) to attach properties to
- * @param  {Object}    class_data  information about the class
+ * @param  {Function}        func              function (class) to set up
+ * @param  {Array.<string>}  abstract_methods  list of abstract method names
  *
  * @return  {undefined}
  */
-function setup_props( func, class_data )
+function setup_props( func, abstract_methods )
 {
-    attach_abstract( func, class_data.abstractMethods );
+    attach_abstract( func, abstract_methods );
     attach_extend( func );
 }