diff --git a/lib/closure_tree/hierarchy_maintenance.rb b/lib/closure_tree/hierarchy_maintenance.rb
index f7c5492d..2278b5a9 100644
--- a/lib/closure_tree/hierarchy_maintenance.rb
+++ b/lib/closure_tree/hierarchy_maintenance.rb
@@ -66,10 +66,10 @@ def rebuild!(called_by_rebuild = false)
         unless root?
           _ct.connection.execute <<-SQL.squish
             INSERT INTO #{_ct.quoted_hierarchy_table_name}
-              (ancestor_id, descendant_id, generations)
-            SELECT x.ancestor_id, #{_ct.quote(_ct_id)}, x.generations + 1
+              (ancestor_id, ancestor_type, descendant_id, descendant_type, generations)
+            SELECT #{_ct.quote(parent.id)}, #{_ct.quote(parent.class.to_s)}, #{_ct.quote(_ct_id)}, x.descendant_type, x.generations + 1
             FROM #{_ct.quoted_hierarchy_table_name} x
-            WHERE x.descendant_id = #{_ct.quote(_ct_parent_id)}
+            WHERE x.descendant_id = #{_ct.quote(_ct_parent_id)} AND x.descendant_type = #{_ct.quote(self.class.to_s)}
           SQL
         end
 
@@ -79,7 +79,7 @@ def rebuild!(called_by_rebuild = false)
           _ct_reorder_siblings if !called_by_rebuild
         end
 
-        children.find_each { |c| c.rebuild!(true) }
+        children.each { |c| c.rebuild!(true) }
 
         _ct_reorder_children if _ct.order_is_numeric? && children.present?
       end
@@ -97,8 +97,8 @@ def delete_hierarchy_references
             SELECT DISTINCT descendant_id
             FROM (SELECT descendant_id
               FROM #{_ct.quoted_hierarchy_table_name}
-              WHERE ancestor_id = #{_ct.quote(id)}
-                 OR descendant_id = #{_ct.quote(id)}
+              WHERE (ancestor_id = #{_ct.quote(id)} AND ancestor_type = #{_ct.quote(self.class.to_s)})
+                 OR (descendant_id = #{_ct.quote(id)} AND descendant_type = #{_ct.quote(self.class.to_s)})
             ) #{ _ct.t_alias_keyword } x )
         SQL
       end
@@ -119,13 +119,15 @@ def cleanup!
         hierarchy_table = hierarchy_class.arel_table
 
         [:descendant_id, :ancestor_id].each do |foreign_key|
-          alias_name = foreign_key.to_s.split('_').first + "s"
+          key_prefix = foreign_key.to_s.split('_')
+          key_as_type = "#{key_prefix}_type".to_sym
+          alias_name = key_prefix.first + "s"
           alias_table = Arel::Table.new(table_name).alias(alias_name)
           arel_join = hierarchy_table.join(alias_table, Arel::Nodes::OuterJoin)
                                      .on(alias_table[primary_key].eq(hierarchy_table[foreign_key]))
                                      .join_sources
 
-          lonely_childs = hierarchy_class.joins(arel_join).where(alias_table[primary_key].eq(nil))
+          lonely_childs = hierarchy_class.joins(arel_join).where(alias_table[primary_key].eq(nil)).where(key_as_type => self.class.to_s)
           ids = lonely_childs.pluck(foreign_key)
 
           hierarchy_class.where(hierarchy_table[foreign_key].in(ids)).delete_all
diff --git a/lib/closure_tree/model.rb b/lib/closure_tree/model.rb
index cc64ae4d..3dd1c76e 100644
--- a/lib/closure_tree/model.rb
+++ b/lib/closure_tree/model.rb
@@ -5,17 +5,19 @@ module Model
     extend ActiveSupport::Concern
 
     included do
-
       belongs_to :parent, nil,
         class_name: _ct.model_class.to_s,
         foreign_key: _ct.parent_column_name,
         inverse_of: :children,
         touch: _ct.options[:touch],
-        optional: true
+        optional: true,
+        polymorphic: true
 
+      where_for_ancestors = { ancestor_type: _ct.model_class.to_s }
+      where_for_descendants = { descendant_type: _ct.model_class.to_s }
       order_by_generations = -> { Arel.sql("#{_ct.quoted_hierarchy_table_name}.generations ASC") }
 
-      has_many :children, *_ct.has_many_order_with_option, **{
+      has_many :children, *_ct.has_many_order_with_option_and_where({ parent_type: _ct.model_class.to_s }), **{
         class_name: _ct.model_class.to_s,
         foreign_key: _ct.parent_column_name,
         dependent: _ct.options[:dependent],
@@ -28,7 +30,7 @@ def hash_tree(options = {})
           end
         end
 
-      has_many :ancestor_hierarchies, *_ct.has_many_order_without_option(order_by_generations),
+      has_many :ancestor_hierarchies, *_ct.has_many_order_without_option_and_where(order_by_generations, where_for_ancestors),
         class_name: _ct.hierarchy_class_name,
         foreign_key: 'descendant_id'
 
@@ -36,13 +38,27 @@ def hash_tree(options = {})
         through: :ancestor_hierarchies,
         source: :ancestor
 
-      has_many :descendant_hierarchies, *_ct.has_many_order_without_option(order_by_generations),
+      has_many :descendant_hierarchies, *_ct.has_many_order_without_option_and_where(order_by_generations, where_for_descendants),
         class_name: _ct.hierarchy_class_name,
         foreign_key: 'ancestor_id'
 
       has_many :self_and_descendants, *_ct.has_many_order_with_option(order_by_generations),
         through: :descendant_hierarchies,
-        source: :descendant
+        source: :descendant, source_type: _ct.model_class.to_s
+    end
+
+    def poly_children
+      pp hierarchy_class.all.map { |h| h.slice(:ancestor_type, :ancestor_id, :descendant_type, :descendant_id, :generations) }
+
+      foo = hierarchy_class
+        .where(ancestor_id: id, ancestor_type: _ct.model_class.to_s, generations: 1)
+        .map { |h_data| { type: h_data.descendant_type, id: h_data.descendant_id } }
+        .group_by { |h_data| h_data[:type] }
+        .map { |type, h_data_array| type.constantize.where(id: h_data_array.map { |h_data| h_data[:id] }) }
+        .flatten
+
+      p foo
+      foo
     end
 
     # Delegate to the Support instance on the class:
diff --git a/lib/closure_tree/support.rb b/lib/closure_tree/support.rb
index e887090e..f4c409ae 100644
--- a/lib/closure_tree/support.rb
+++ b/lib/closure_tree/support.rb
@@ -36,11 +36,10 @@ def hierarchy_class_for_model
       hierarchy_class = parent_class.const_set(short_hierarchy_class_name, Class.new(model_class.superclass))
       use_attr_accessible = use_attr_accessible?
       include_forbidden_attributes_protection = include_forbidden_attributes_protection?
-      model_class_name = model_class.to_s
       hierarchy_class.class_eval do
         include ActiveModel::ForbiddenAttributesProtection if include_forbidden_attributes_protection
-        belongs_to :ancestor, class_name: model_class_name
-        belongs_to :descendant, class_name: model_class_name
+        belongs_to :ancestor, polymorphic: true
+        belongs_to :descendant, polymorphic: true
         attr_accessible :ancestor, :descendant, :generations if use_attr_accessible
         def ==(other)
           self.class == other.class && ancestor_id == other.ancestor_id && descendant_id == other.descendant_id
@@ -58,8 +57,7 @@ def hierarchy_table_name
       # We need to use the table_name, not something like ct_class.to_s.demodulize + "_hierarchies",
       # because they may have overridden the table name, which is what we want to be consistent with
       # in order for the schema to make sense.
-      tablename = options[:hierarchy_table_name] ||
-        remove_prefix_and_suffix(table_name).singularize + "_hierarchies"
+      tablename = "hierarchies"
 
       ActiveRecord::Base.table_name_prefix + tablename + ActiveRecord::Base.table_name_suffix
     end
@@ -84,6 +82,10 @@ def has_many_order_without_option(order_by_opt)
       [lambda { order(order_by_opt.call) }]
     end
 
+    def has_many_order_without_option_and_where(order_by_opt, where_clause)
+      [lambda { where(where_clause).order(order_by_opt.call) }]
+    end
+
     def has_many_order_with_option(order_by_opt=nil)
       order_options = [order_by_opt, order_by].compact
       [lambda {
@@ -92,6 +94,14 @@ def has_many_order_with_option(order_by_opt=nil)
       }]
     end
 
+    def has_many_order_with_option_and_where(order_by_opt=nil, where_clause)
+      order_options = [order_by_opt, order_by].compact
+      [lambda {
+        order_options = order_options.map { |o| o.is_a?(Proc) ? o.call : o }
+        where(where_clause).order(order_options)
+      }]
+    end
+
     def ids_from(scope)
       scope.pluck(model_class.primary_key)
     end
diff --git a/lib/closure_tree/support_attributes.rb b/lib/closure_tree/support_attributes.rb
index 38879ade..162518fa 100644
--- a/lib/closure_tree/support_attributes.rb
+++ b/lib/closure_tree/support_attributes.rb
@@ -17,7 +17,7 @@ def quoted_value(value)
     end
 
     def hierarchy_class_name
-      options[:hierarchy_class_name] || model_class.to_s + "Hierarchy"
+      "Hierarchy"
     end
 
     def primary_key_column
diff --git a/lib/generators/closure_tree/templates/create_hierarchies_table.rb.erb b/lib/generators/closure_tree/templates/create_hierarchies_table.rb.erb
index 18d7671c..56f69173 100644
--- a/lib/generators/closure_tree/templates/create_hierarchies_table.rb.erb
+++ b/lib/generators/closure_tree/templates/create_hierarchies_table.rb.erb
@@ -1,16 +1,18 @@
 class <%= migration_class_name %> < ActiveRecord::Migration<%= migration_version %>
   def change
-    create_table :<%= migration_name %>, id: false do |t|
+    create_table :hierarchies, id: false do |t|
       t.<%= primary_key_type %> :ancestor_id, null: false
+      t.string :ancestor_type, null: false
       t.<%= primary_key_type %> :descendant_id, null: false
+      t.string :descendant_type, null: false
       t.integer :generations, null: false
     end
 
-    add_index :<%= migration_name %>, [:ancestor_id, :descendant_id, :generations],
+    add_index :hierarchies, [:ancestor_id, :ancestor_type, :descendant_id, :descendant_type, :generations],
       unique: true,
-      name: "<%= file_name %>_anc_desc_idx"
+      name: "anc_desc_idx"
 
-    add_index :<%= migration_name -%>, [:descendant_id],
-      name: "<%= file_name %>_desc_idx"
+    add_index :hierarchies, [:descendant_id],
+      name: "desc_idx"
   end
 end