diff --git a/lib/plugins/acts_as_tree/lib/active_record/acts/tree.rb b/lib/plugins/acts_as_tree/lib/active_record/acts/tree.rb
index 4e5f37182..d069da972 100644
--- a/lib/plugins/acts_as_tree/lib/active_record/acts/tree.rb
+++ b/lib/plugins/acts_as_tree/lib/active_record/acts/tree.rb
@@ -47,6 +47,8 @@ module ActiveRecord
           has_many :children, :class_name => name, :foreign_key => configuration[:foreign_key], :order => configuration[:order], :dependent => configuration[:dependent]
 
           scope :roots, where("#{configuration[:foreign_key]} IS NULL").order(configuration[:order])
+
+          send :include, ActiveRecord::Acts::Tree::InstanceMethods
         end
       end