diff --git a/app/models/enumeration.rb b/app/models/enumeration.rb
index 1c4a7a4..fde7ea7 100644
--- a/app/models/enumeration.rb
+++ b/app/models/enumeration.rb
@@ -24,7 +24,7 @@ class Enumeration < ActiveRecord::Base
 
   acts_as_list :scope => 'type = \'#{type}\''
   acts_as_customizable
-  acts_as_tree :order => 'position ASC'
+  acts_as_tree :order => "#{Enumeration.table_name}.position ASC"
 
   before_destroy :check_integrity
   before_save    :check_default