diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index feb7d228..57ad5180 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -69,7 +69,12 @@ end
 
       def attributes(*attrs)
         @_attributes.concat attrs
-        attrs.each{|attr| define_attribute_accessor(attr)}
+
+        attrs.each do |attr|
+          define_method attr do
+            object.read_attribute_for_serialization attr
+          end unless method_defined?(attr)
+        end
       end
 
       def has_one(*attrs)
@@ -86,27 +91,13 @@ end
         options = attrs.extract_options!
 
         attrs.each do |attr|
-          define_association_accessor(attr)
+          define_method attr do
+            object.send attr
+          end unless method_defined?(attr)
+
           @_associations[attr] = klass.new(attr, options)
         end
       end
-
-      def define_accessor_unless_defined(attr, &block)
-        return if method_defined?(attr)
-        define_method(attr, &block)
-      end
-
-      def define_attribute_accessor(attr)
-        define_accessor_unless_defined(attr) do
-          object.read_attribute_for_serialization(attr)
-        end
-      end
-
-      def define_association_accessor(attr)
-        define_accessor_unless_defined(attr) do
-          object.__send__(attr)
-        end
-      end
     end
 
     def initialize(object, options={})