diff --git a/lib/acl9/model_extensions.rb b/lib/acl9/model_extensions.rb
index a529ba6..d55d0f9 100644
--- a/lib/acl9/model_extensions.rb
+++ b/lib/acl9/model_extensions.rb
@@ -16,6 +16,8 @@ module ClassMethods
       #                           Class name of the role class (e.g. 'AccountRole')
       # @option options [String] :join_table_name (Acl9::config[:default_join_table_name])
       #                           Join table name (e.g. 'accounts_account_roles')
+      # @option options [String] :association_name (Acl9::config[:default_association_name])
+      #														Association name (e.g. ':roles')
       # @example
       #   class User < ActiveRecord::Base
       #     acts_as_authorization_subject