diff --git a/.gitignore b/.gitignore
index 3c2860b..7338873 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,6 @@ pkg/
 .idea/*
 *.db
 tmp/fixture_builder.yml
-test/fixtures/magical_creatures.yml
+test/fixtures/**/*.yml
 Gemfile.lock
 *.gem
diff --git a/lib/fixture_builder/builder.rb b/lib/fixture_builder/builder.rb
index 83e5d9a..cbe34f8 100644
--- a/lib/fixture_builder/builder.rb
+++ b/lib/fixture_builder/builder.rb
@@ -92,38 +92,33 @@ def dump_empty_fixtures_for_all_tables
     end
 
     def dump_tables
-      default_date_format = Date::DATE_FORMATS[:default]
-      Date::DATE_FORMATS[:default] = Date::DATE_FORMATS[:db]
-      begin
-        fixtures = tables.inject([]) do |files, table_name|
-          table_klass = table_name.classify.constantize rescue nil
-          if table_klass && table_klass < ActiveRecord::Base
-            rows = table_klass.unscoped do
-              table_klass.order(:id).all.collect do |obj|
-                attrs = obj.attributes.select { |attr_name| table_klass.column_names.include?(attr_name) }
-                attrs.inject({}) do |hash, (attr_name, value)|
-                  hash[attr_name] = serialized_value_if_needed(table_klass, attr_name, value)
-                  hash
-                end
+      fixtures = tables.inject([]) do |files, table_name|
+        table_klass = fixture_classes[table_name] || table_name.classify.constantize rescue nil
+        if table_klass && table_klass < ActiveRecord::Base
+          rows = table_klass.unscoped do
+            table_klass.order(:id).all.collect do |obj|
+              attrs = obj.attributes.select { |attr_name| table_klass.column_names.include?(attr_name) }
+              attrs.inject({}) do |hash, (attr_name, value)|
+                hash[attr_name] = serialized_value_if_needed(table_klass, attr_name, value)
+                hash
               end
             end
-          else
-            rows = ActiveRecord::Base.connection.select_all(select_sql % {table: ActiveRecord::Base.connection.quote_table_name(table_name)})
           end
-          next files if rows.empty?
+        else
+          rows = ActiveRecord::Base.connection.select_all(select_sql % {table: ActiveRecord::Base.connection.quote_table_name(table_name)})
+        end
+        next files if rows.empty?
 
-          row_index = '000'
-          fixture_data = rows.inject({}) do |hash, record|
-            hash.merge(record_name(record, table_name, row_index) => record)
-          end
+        row_index = '000'
+        fixture_data = rows.inject({}) do |hash, record|
+          hash.merge(record_name(record, table_name, row_index) => record)
+        end
 
-          write_fixture_file fixture_data, table_name
+        write_fixture_file fixture_data, table_name
 
-          files + [File.basename(fixture_file(table_name))]
-        end
-      ensure
-        Date::DATE_FORMATS[:default] = default_date_format
+        files + [File.basename(fixture_file(table_name))]
       end
+
       say "Built #{fixtures.to_sentence}"
     end
 
@@ -154,7 +149,8 @@ def write_fixture_file(fixture_data, table_name)
     end
 
     def fixture_file(table_name)
-      fixtures_dir("#{table_name}.yml")
+      file_name = fixture_files[table_name] || table_name
+      fixtures_dir("#{file_name}.yml")
     end
   end
 end
diff --git a/lib/fixture_builder/configuration.rb b/lib/fixture_builder/configuration.rb
index 056d29c..c582230 100644
--- a/lib/fixture_builder/configuration.rb
+++ b/lib/fixture_builder/configuration.rb
@@ -110,7 +110,45 @@ def fixture_directory
     end
 
     def fixtures_dir(path = '')
-      File.expand_path(File.join(fixture_directory, path))
+      subdirs = path.split('/')
+      path = subdirs.pop || ''
+      dir = File.expand_path(File.join(fixture_directory, *subdirs))
+
+      FileUtils.mkdir_p(dir)
+      File.join(dir, path)
+    end
+
+    # This allows for configuring fixtures for a given database table; you may
+    # set the model class for the table (e.g. for legacy tables) and the name
+    # of the resulting fixture file for the table (e.g. for nested fixtures).
+    #
+    # For example:
+    #
+    #   FixtureBuilder.configure do |fbuilder|
+    #     fbuilder.configure_tables(wibbles: {
+    #       class: Legacy::Things,
+    #       file: 'legacy/things'
+    #     })
+    #   end
+    #
+    # This will tell the builder to use the `Legacy::Things` class to serialize
+    # fixtured dumped from the `wibbles` table, and to dump the `wibbles` table
+    # into the `legacy_things.yml` file.  This also works with nested
+    # directories, which will map to namespaced fixtures.
+    def configure_tables(configuration)
+      configuration.each do |table_name, table_config|
+        table_name = table_name.to_s
+        fixture_classes.merge!(table_name => table_config[:class])
+        fixture_files.merge!(table_name => table_config[:file])
+      end
+    end
+
+    def fixture_classes
+      @fixture_classes ||= {}
+    end
+
+    def fixture_files
+      @fixture_files ||= {}
     end
 
     private
diff --git a/lib/fixture_builder/delegations.rb b/lib/fixture_builder/delegations.rb
index ad39a26..81b2bc9 100644
--- a/lib/fixture_builder/delegations.rb
+++ b/lib/fixture_builder/delegations.rb
@@ -4,7 +4,7 @@ module FixtureBuilder
   module Delegations
     module Configuration
       def self.included(base)
-        methods_to_delegate = [:fixtures_dir, :tables, :legacy_fixtures].concat(::FixtureBuilder::Configuration::ACCESSIBLE_ATTRIBUTES).flatten
+        methods_to_delegate = [:fixtures_dir, :tables, :legacy_fixtures, :fixture_classes, :fixture_files].concat(::FixtureBuilder::Configuration::ACCESSIBLE_ATTRIBUTES).flatten
         methods_to_delegate.each do |meth|
           base.delegate(meth, :to => :@configuration)
         end
diff --git a/lib/fixture_builder/namer.rb b/lib/fixture_builder/namer.rb
index 953faf8..b611559 100644
--- a/lib/fixture_builder/namer.rb
+++ b/lib/fixture_builder/namer.rb
@@ -17,7 +17,7 @@ def name(custom_name, *model_objects)
       raise "Cannot name an object blank" unless custom_name.present?
       model_objects.each do |model_object|
         raise "Cannot name a blank object" unless model_object.present?
-        key = [model_object.class.table_name, model_object.id]
+        key = [model_object.class.table_name, model_object.id.to_s]
         raise "Cannot set name for #{key.inspect} object twice" if @custom_names[key]
         @custom_names[key] = custom_name
         model_object
@@ -34,7 +34,7 @@ def populate_custom_names(created_fixtures)
       # Rails 3.0 and earlier, create_fixtures returns an array of tuples
       created_fixtures.each do |fixture|
         name = fixture[0]
-        id = fixture[1]['id'].to_i
+        id = fixture[1]['id'].to_s
         table_name = fixture[1].model_class.table_name
         key = [table_name, id]
         @custom_names[key] = name
@@ -42,7 +42,7 @@ def populate_custom_names(created_fixtures)
     end
 
     def record_name(record_hash, table_name, row_index)
-      key = [table_name, record_hash['id'].to_i]
+      key = [table_name, record_hash['id'].to_s]
       name = case
                when name_proc = @model_name_procs[table_name]
                  name_proc.call(record_hash, row_index.succ!)
diff --git a/test/fixture_builder_test.rb b/test/fixture_builder_test.rb
index eac005d..87a317c 100644
--- a/test/fixture_builder_test.rb
+++ b/test/fixture_builder_test.rb
@@ -38,6 +38,20 @@ def test_ivar_naming
     assert_equal 'king_of_gnomes', generated_fixture.keys.first
   end
 
+  def test_ivar_naming_with_uuid_primary_key
+    create_and_blow_away_old_db
+    force_fixture_generation
+
+    FixtureBuilder.configure do |fbuilder|
+      fbuilder.files_to_check += Dir[test_path("*.rb")]
+      fbuilder.factory do
+        @you_know_who = Unnameable.create!
+      end
+    end
+    generated_fixture = YAML.load(File.open(test_path("fixtures/unnameables.yml")))
+    assert_equal 'you_know_who', generated_fixture.keys.first
+  end
+
   def test_serialization
     create_and_blow_away_old_db
     force_fixture_generation
@@ -80,7 +94,13 @@ def test_absolute_rails_fixtures_path
   end
 
   def test_fixtures_dir
-    assert_match /test\/fixtures$/, FixtureBuilder.configuration.send(:fixtures_dir).to_s
+    file_path = "wibble.yml"
+    assert_match(/test\/fixtures\/#{file_path}$/, FixtureBuilder.configuration.send(:fixtures_dir, file_path).to_s)
+  end
+
+  def test_nested_fixtures_dir
+    file_path = "foo/bar/wibble.yml"
+    assert_match(/test\/fixtures\/#{file_path}$/, FixtureBuilder.configuration.send(:fixtures_dir, file_path).to_s)
   end
 
   def test_rebuilding_due_to_differing_file_hashes
@@ -115,4 +135,64 @@ def test_sha1_digests
       assert_equal first_modified_time, second_modified_time
     end
   end
+
+  def test_set_fixture_class
+    create_and_blow_away_old_db
+    force_fixture_generation
+
+    old_klass = MagicalCreature
+    new_klass = Class.new(ActiveRecord::Base) do
+      self.table_name = "magical_creatures"
+      serialize :powers, Array
+    end
+    Object.instance_eval { remove_const(:MagicalCreature) }
+
+    FixtureBuilder.configure do |fbuilder|
+      fbuilder.configure_tables(magical_creatures: { class: new_klass })
+
+      fbuilder.files_to_check += Dir[test_path("*.rb")]
+      fbuilder.factory do
+        @enty = new_klass.create(:name => 'Enty', :species => 'ent',
+                                        :powers => %w{shading rooting seeding})
+      end
+    end
+    generated_fixture = YAML.load(File.open(test_path("fixtures/magical_creatures.yml")))
+    assert_equal "---\n- shading\n- rooting\n- seeding\n", generated_fixture['enty']['powers']
+  ensure
+    Object.const_set(:MagicalCreature, old_klass)
+  end
+
+  def test_set_fixture_file
+    create_and_blow_away_old_db
+    force_fixture_generation
+
+    FixtureBuilder.configure do |fbuilder|
+      fbuilder.configure_tables(magical_creatures: { file: "wibbles" })
+
+      fbuilder.files_to_check += Dir[test_path("*.rb")]
+      fbuilder.factory do
+        @enty = MagicalCreature.create(:name => 'Enty', :species => 'ent',
+                                        :powers => %w{shading rooting seeding})
+      end
+    end
+    generated_fixture = YAML.load(File.open(test_path("fixtures/wibbles.yml")))
+    assert_equal "---\n- shading\n- rooting\n- seeding\n", generated_fixture['enty']['powers']
+  end
+
+  def test_set_fixture_file_with_namespace
+    create_and_blow_away_old_db
+    force_fixture_generation
+
+    FixtureBuilder.configure do |fbuilder|
+      fbuilder.configure_tables(magical_creatures: { file: "legacy/wibbles" })
+
+      fbuilder.files_to_check += Dir[test_path("*.rb")]
+      fbuilder.factory do
+        @enty = MagicalCreature.create(:name => 'Enty', :species => 'ent',
+                                        :powers => %w{shading rooting seeding})
+      end
+    end
+    generated_fixture = YAML.load(File.open(test_path("fixtures/legacy/wibbles.yml")))
+    assert_equal "---\n- shading\n- rooting\n- seeding\n", generated_fixture['enty']['powers']
+  end
 end
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 778720a..be9b698 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -40,19 +40,34 @@ class MagicalCreature < ActiveRecord::Base
   end
 end
 
+class Unnameable < ActiveRecord::Base; end
+
 def create_and_blow_away_old_db
-  ActiveRecord::Base.configurations['test'] = {
-      'adapter' => 'sqlite3',
-      'database' => 'test.db'
-  }
+  if ActiveRecord::VERSION::MAJOR >= 7
+    ActiveRecord::Base.configurations = {
+      test: {
+        'adapter' => 'sqlite3',
+        'database' => 'test.db'
+      }
+    }
+  else
+    ActiveRecord::Base.configurations['test'] = {
+        'adapter' => 'sqlite3',
+        'database' => 'test.db'
+    }
+  end
   ActiveRecord::Base.establish_connection(:test)
 
-  ActiveRecord::Base.connection.create_table(:magical_creatures, :force => true) do |t|
+  ActiveRecord::Base.connection.create_table(:magical_creatures, force: true) do |t|
     t.column :name, :string
     t.column :species, :string
     t.column :powers, :string
     t.column :deleted, :boolean, :default => false, :null => false
   end
+
+  ActiveRecord::Base.connection.create_table(:unnameables, force: true, id: false) do |t|
+    t.column :id, :uuid, primary: true
+  end
 end
 
 def force_fixture_generation