diff --git a/lib/closure_tree/acts_as_tree.rb b/lib/closure_tree/acts_as_tree.rb
index eef1ea2e..7cfd3ec9 100644
--- a/lib/closure_tree/acts_as_tree.rb
+++ b/lib/closure_tree/acts_as_tree.rb
@@ -120,7 +120,7 @@ def descendants
     end
 
     def self_and_siblings
-      self.class.scoped.where(:parent => parent)
+      self.class.scoped.where(:parent_id => parent)
     end
 
     def siblings