diff --git a/lib/pagseguro/order.rb b/lib/pagseguro/order.rb
index 50a1191..90fade9 100644
--- a/lib/pagseguro/order.rb
+++ b/lib/pagseguro/order.rb
@@ -13,10 +13,12 @@ class Order
       :address_country       => "cliente_pais",
       :phone_area_code       => "cliente_ddd",
       :phone_number          => "cliente_tel",
-      :email                 => "cliente_email",
-      :extra_amount          => "extra_amount"
+      :email                 => "cliente_email"
     }
 
+    # The list of products added to the order
+    attr_accessor :extra_amount
+    
     # The list of products added to the order
     attr_accessor :products