diff --git a/lib/patches/ancestry_patch.rb b/lib/patches/ancestry_patch.rb
index fb9781261fb..ce65a76c0bd 100644
--- a/lib/patches/ancestry_patch.rb
+++ b/lib/patches/ancestry_patch.rb
@@ -1,10 +1,27 @@
+module AncestryInstanceMethodsPatch
+  def update_descendants_with_new_ancestry
+    super
+    unless ancestry_callbacks_disabled?
+      if ancestry_changed? && !new_record? && sane_ancestry?
+        self.clear_memoized_instance_variables
+        unscoped_descendants.each(&:clear_memoized_instance_variables)
+      end
+    end
+  end
+end
+
 module Ancestry
   module InstanceMethods
+    prepend AncestryInstanceMethodsPatch
 
     def parse_ancestry_column obj
       obj.to_s.split('/').map! { |id| cast_primary_key(id) }
     end
 
+    def ancestor_ids
+      @_ancestor_ids ||= parse_ancestry_column(read_attribute(self.ancestry_base_class.ancestry_column))
+    end
+
     STRING_BASED_KEYS = [:string, :uuid, :text].freeze
     def cast_primary_key(key)
       if STRING_BASED_KEYS.include? primary_key_type
@@ -14,5 +31,9 @@ def cast_primary_key(key)
       end
     end
 
+    def clear_memoized_instance_variables
+      @_ancestor_ids = nil
+    end
+
   end
 end