diff --git a/app/models/page_context.rb b/app/models/page_context.rb
index 5520379..9d0d2b6 100644
--- a/app/models/page_context.rb
+++ b/app/models/page_context.rb
@@ -4,6 +4,7 @@ class PageContext
   include Mongoid::Document
   include Mongoid::Timestamps
   include OrbitModel::Impression
+  include AutoConvertUnitHelper
 
   field :update_user_id
   field :version, :type => Integer , :default => 0