diff --git a/app/models/document.rb b/app/models/document.rb
index 208b10876..0917f8449 100644
--- a/app/models/document.rb
+++ b/app/models/document.rb
@@ -45,7 +45,7 @@ class Document < ActiveRecord::Base
 
   def updated_on
     unless @updated_on
-      a = attachments.find(:first, :order => 'created_on DESC')
+      a = attachments.last
       @updated_on = (a && a.created_on) || created_on
     end
     @updated_on