diff --git a/Gemfile.lock b/Gemfile.lock
index 302d361..101aceb 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -8,7 +8,7 @@ GIT
 
 GIT
   remote: https://github.com/corp-gp/rubocop-gp.git
-  revision: 61d6ca243e1a5f7d209e9619417c8fc1d303d181
+  revision: 867f7e1351c3730897cacdc20ce2d727604de245
   specs:
     rubocop-gp (0.0.4)
       rubocop
@@ -73,20 +73,20 @@ GEM
       zeitwerk (~> 2.6)
     i18n (1.14.6)
       concurrent-ruby (~> 1.0)
-    json (2.7.2)
+    json (2.8.2)
     language_server-protocol (3.17.0.3)
     logger (1.6.1)
     method_source (1.1.0)
-    minitest (5.25.1)
+    minitest (5.25.2)
     parallel (1.26.3)
-    parser (3.3.5.0)
+    parser (3.3.6.0)
       ast (~> 2.4.1)
       racc
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
     racc (1.8.1)
-    rack (3.1.7)
+    rack (3.1.8)
     rainbow (3.1.1)
     rake (13.2.1)
     regexp_parser (2.9.2)
@@ -103,49 +103,52 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
     rspec-support (3.13.1)
-    rubocop (1.66.1)
+    rubocop (1.69.0)
       json (~> 2.3)
       language_server-protocol (>= 3.17.0)
       parallel (~> 1.10)
       parser (>= 3.3.0.2)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 2.4, < 3.0)
-      rubocop-ast (>= 1.32.2, < 2.0)
+      rubocop-ast (>= 1.36.1, < 2.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.32.3)
+      unicode-display_width (>= 2.4.0, < 4.0)
+    rubocop-ast (1.36.1)
       parser (>= 3.3.1.0)
     rubocop-capybara (2.21.0)
       rubocop (~> 1.41)
     rubocop-factory_bot (2.26.1)
       rubocop (~> 1.61)
-    rubocop-performance (1.22.1)
+    rubocop-performance (1.23.0)
       rubocop (>= 1.48.1, < 2.0)
       rubocop-ast (>= 1.31.1, < 2.0)
-    rubocop-rails (2.26.2)
+    rubocop-rails (2.27.0)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.52.0, < 2.0)
       rubocop-ast (>= 1.31.1, < 2.0)
-    rubocop-rspec (3.0.5)
+    rubocop-rspec (3.2.0)
       rubocop (~> 1.61)
     rubocop-rspec_rails (2.30.0)
       rubocop (~> 1.61)
       rubocop-rspec (~> 3, >= 3.0.1)
     ruby-progressbar (1.13.0)
     rumoji (0.5.0)
-    securerandom (0.3.1)
+    securerandom (0.3.2)
     sqlite3 (1.7.3-arm64-darwin)
     sqlite3 (1.7.3-x86_64-darwin)
     sqlite3 (1.7.3-x86_64-linux)
     timeout (0.4.1)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    unicode-display_width (2.6.0)
+    unicode-display_width (3.1.2)
+      unicode-emoji (~> 4.0, >= 4.0.4)
+    unicode-emoji (4.0.4)
     zeitwerk (2.6.18)
 
 PLATFORMS
   arm64-darwin-21
+  arm64-darwin-23
   x86_64-darwin-21
   x86_64-linux
 
diff --git a/README.md b/README.md
index 1af78a1..38583ad 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
-# Enum machine
+# Enum Machine
 
-Enum machine is a library for defining enums and setting state machines for attributes in ActiveRecord models and plain Ruby classes.
+`Enum Machine` is a library for defining enums and setting state machines for attributes in ActiveRecord models and plain Ruby classes.
 
 You can visualize transitions map with [enum_machine-contrib](https://github.com/corp-gp/enum_machine-contrib)
 
@@ -29,7 +29,7 @@ end
 
 order = Order.create(state: "collecting")
 order.update(state: "archived") # not check transitions, invalid logic
-order.update(state: "collected") # not run callbacks 
+order.update(state: "collected") # not run callbacks
 order.complete # need use event for transition, but your object in UI and DB have only states
 
 # enum_machine
@@ -66,7 +66,7 @@ end
 class Product
   # attributes must be defined before including the EnumMachine module
   attr_accessor :color
-  
+
   include EnumMachine[color: { enum: %w[red green] }]
   # or reuse from model
   Product::COLOR.decorator_module
@@ -76,6 +76,9 @@ Product::COLOR.values # => ["red", "green"]
 Product::COLOR::RED # => "red"
 Product::COLOR::RED__GREEN # => ["red", "green"]
 
+Product::COLOR["red"].red? # => true
+Product::COLOR["red"].human_name # => "Красный"
+
 product = Product.new
 product.color # => nil
 product.color = "red"
@@ -100,6 +103,35 @@ product = Product.new(state: "created")
 product.state.forming? # => true
 ```
 
+### Value decorator
+
+You can extend value object with decorator
+
+```ruby
+# Value classes nested from base class
+module ColorDecorator
+  def hex
+    case self
+    when Product::COLOR::RED then "#ff0000"
+    when Product::COLOR::GREEN then "#00ff00"
+    end
+  end
+end
+
+class Product
+  attr_accessor :color
+
+  include EnumMachine[color: {
+    enum:      %w[red green],
+    decorator: ColorDecorator
+  }]
+end
+
+product = Product.new
+product.color = "red"
+product.color.hex # => "#ff0000"
+```
+
 ### Transitions
 
 ```ruby
diff --git a/lib/enum_machine.rb b/lib/enum_machine.rb
index 63c32c7..a5db28c 100644
--- a/lib/enum_machine.rb
+++ b/lib/enum_machine.rb
@@ -9,11 +9,9 @@
 require "active_support"
 
 module EnumMachine
-
   class Error < StandardError; end
 
   class InvalidTransition < Error
-
     attr_reader :from, :to, :enum_const
 
     def initialize(machine, from, to)
@@ -26,13 +24,11 @@ def initialize(machine, from, to)
         end
       super("Transition #{from.inspect} => #{to.inspect} not defined in enum_machine :#{machine.attr_name}")
     end
-
   end
 
   def self.[](args)
     DriverSimpleClass.call(args)
   end
-
 end
 
 ActiveSupport.on_load(:active_record) do
diff --git a/lib/enum_machine/attribute_persistence_methods.rb b/lib/enum_machine/attribute_persistence_methods.rb
index e845ba7..8d1bfce 100644
--- a/lib/enum_machine/attribute_persistence_methods.rb
+++ b/lib/enum_machine/attribute_persistence_methods.rb
@@ -2,16 +2,11 @@
 
 module EnumMachine
   module AttributePersistenceMethods
-
     def self.[](attr, enum_values)
       Module.new do
         define_singleton_method(:extended) do |klass|
           klass.attr_accessor :parent
 
-          klass.define_method(:inspect) do
-            "#<EnumMachine:BuildAttribute value=#{self} parent=#{parent.inspect}>"
-          end
-
           enum_values.each do |enum_value|
             enum_name = enum_value.underscore
 
@@ -28,6 +23,5 @@ def to_#{enum_name}!
         end
       end
     end
-
   end
 end
diff --git a/lib/enum_machine/build_attribute.rb b/lib/enum_machine/build_attribute.rb
index 539b0bc..e810a69 100644
--- a/lib/enum_machine/build_attribute.rb
+++ b/lib/enum_machine/build_attribute.rb
@@ -2,15 +2,16 @@
 
 module EnumMachine
   module BuildAttribute
-
-    def self.call(enum_values:, i18n_scope:, machine: nil)
+    def self.call(enum_values:, i18n_scope:, decorator:, machine: nil)
       aliases = machine&.instance_variable_get(:@aliases) || {}
 
       Class.new(String) do
+        include(decorator) if decorator
+
         define_method(:machine) { machine } if machine
 
         def inspect
-          "#<EnumMachine:BuildAttribute value=#{self}>"
+          "#<EnumMachine \"#{self}\">"
         end
 
         if machine&.transitions?
@@ -74,6 +75,5 @@ def human_name
         end
       end
     end
-
   end
 end
diff --git a/lib/enum_machine/build_class.rb b/lib/enum_machine/build_class.rb
index b3b8129..fc2667a 100644
--- a/lib/enum_machine/build_class.rb
+++ b/lib/enum_machine/build_class.rb
@@ -2,13 +2,20 @@
 
 module EnumMachine
   module BuildClass
-
-    def self.call(enum_values:, i18n_scope:, machine: nil)
+    def self.call(enum_values:, i18n_scope:, value_class:, machine: nil)
       aliases = machine&.instance_variable_get(:@aliases) || {}
 
       Class.new do
         define_singleton_method(:machine) { machine } if machine
-        define_singleton_method(:values) { enum_values }
+        define_singleton_method(:values) { enum_values.map { value_class.new(_1).freeze } }
+
+        value_attribute_mapping = values.to_h { [_1.to_s, _1] }
+        define_singleton_method(:value_attribute_mapping) { value_attribute_mapping }
+        define_singleton_method(:[]) do |enum_value|
+          key = enum_value.to_s
+          # Check for key existence because `[]` will call `default_proc`, and we don’t want that
+          value_attribute_mapping[key] if value_attribute_mapping.key?(key)
+        end
 
         if i18n_scope
           def self.values_for_form(specific_values = nil) # rubocop:disable Gp/OptArgParameters
@@ -27,7 +34,7 @@ def self.human_name_for(name)
         end
 
         enum_values.each do |enum_value|
-          const_set enum_value.underscore.upcase, enum_value.freeze
+          const_set enum_value.underscore.upcase, enum_value.to_s.freeze
         end
 
         aliases.each_key do |key|
@@ -50,6 +57,5 @@ def self.#{key}
         end
       end
     end
-
   end
 end
diff --git a/lib/enum_machine/driver_active_record.rb b/lib/enum_machine/driver_active_record.rb
index 3de63d0..5368db3 100644
--- a/lib/enum_machine/driver_active_record.rb
+++ b/lib/enum_machine/driver_active_record.rb
@@ -2,8 +2,7 @@
 
 module EnumMachine
   module DriverActiveRecord
-
-    def enum_machine(attr, enum_values, i18n_scope: nil, &block)
+    def enum_machine(attr, enum_values, i18n_scope: nil, decorator: nil, &block)
       klass = self
 
       i18n_scope ||= "#{klass.base_class.to_s.underscore}.#{attr}"
@@ -12,16 +11,16 @@ def enum_machine(attr, enum_values, i18n_scope: nil, &block)
       machine = Machine.new(enum_values, klass, enum_const_name, attr)
       machine.instance_eval(&block) if block
 
-      enum_klass = BuildClass.call(enum_values: enum_values, i18n_scope: i18n_scope, machine: machine)
-
-      enum_value_klass = BuildAttribute.call(enum_values: enum_values, i18n_scope: i18n_scope, machine: machine)
-      enum_value_klass.extend(AttributePersistenceMethods[attr, enum_values])
+      value_class = BuildAttribute.call(enum_values: enum_values, i18n_scope: i18n_scope, machine: machine, decorator: decorator)
+      enum_klass = BuildClass.call(enum_values: enum_values, i18n_scope: i18n_scope, machine: machine, value_class: value_class)
 
-      enum_klass.const_set :VALUE_KLASS, enum_value_klass
+      value_class.extend(AttributePersistenceMethods[attr, enum_values])
 
-      # Hash.new with default_proc for working with custom values not defined in enum list
-      value_attribute_mapping = Hash.new { |hash, enum_value| hash[enum_value] = enum_klass::VALUE_KLASS.new(enum_value).freeze }
-      enum_klass.define_singleton_method(:value_attribute_mapping) { value_attribute_mapping }
+      # default_proc for working with custom values not defined in enum list but may exists in db
+      enum_klass.value_attribute_mapping.default_proc =
+        proc do |hash, enum_value|
+          hash[enum_value] = value_class.new(enum_value).freeze
+        end
 
       if machine.transitions?
         klass.class_eval <<-RUBY, __FILE__, __LINE__ + 1 # rubocop:disable Style/DocumentDynamicEvalDefinition
@@ -114,6 +113,5 @@ def initialize_dup(other)
 
       enum_decorator
     end
-
   end
 end
diff --git a/lib/enum_machine/driver_simple_class.rb b/lib/enum_machine/driver_simple_class.rb
index 2d81fd9..6a566c5 100644
--- a/lib/enum_machine/driver_simple_class.rb
+++ b/lib/enum_machine/driver_simple_class.rb
@@ -2,7 +2,6 @@
 
 module EnumMachine
   module DriverSimpleClass
-
     # include EnumMachine[
     #   state: { enum: %w[choice in_delivery], i18n_scope: 'line_item.state' },
     #   color: { enum: %w[red green yellow] },
@@ -14,17 +13,14 @@ def self.call(args)
           args.each do |attr, params|
             enum_values  = params.fetch(:enum)
             i18n_scope   = params.fetch(:i18n_scope, nil)
+            decorator    = params.fetch(:decorator, nil)
 
             if defined?(ActiveRecord) && klass <= ActiveRecord::Base
               klass.enum_machine(attr, enum_values, i18n_scope: i18n_scope)
             else
               enum_const_name = attr.to_s.upcase
-              enum_klass = BuildClass.call(enum_values: enum_values, i18n_scope: i18n_scope)
-
-              enum_value_klass = BuildAttribute.call(enum_values: enum_values, i18n_scope: i18n_scope)
-              enum_klass.const_set :VALUE_KLASS, enum_value_klass
-
-              value_attribute_mapping = enum_values.to_h { |enum_value| [enum_value, enum_klass::VALUE_KLASS.new(enum_value).freeze] }
+              value_class = BuildAttribute.call(enum_values: enum_values, i18n_scope: i18n_scope, decorator: decorator)
+              enum_klass = BuildClass.call(enum_values: enum_values, i18n_scope: i18n_scope, value_class: value_class)
 
               define_methods =
                 Module.new do
@@ -32,7 +28,7 @@ def self.call(args)
                     enum_value = super()
                     return unless enum_value
 
-                    value_attribute_mapping.fetch(enum_value)
+                    enum_klass.value_attribute_mapping.fetch(enum_value)
                   end
                 end
 
@@ -52,6 +48,5 @@ def self.call(args)
         end
       end
     end
-
   end
 end
diff --git a/lib/enum_machine/machine.rb b/lib/enum_machine/machine.rb
index c7e5118..7e5dea5 100644
--- a/lib/enum_machine/machine.rb
+++ b/lib/enum_machine/machine.rb
@@ -2,7 +2,6 @@
 
 module EnumMachine
   class Machine
-
     attr_reader :enum_values, :base_klass, :enum_const_name, :attr_name
 
     def initialize(enum_values, base_klass = nil, enum_const_name = nil, attr_name = nil) # rubocop:disable Gp/OptArgParameters
@@ -132,8 +131,6 @@ def possible_transitions(from)
     end
 
     class AnyEnumValues < Array
-
     end
-
   end
 end
diff --git a/lib/enum_machine/version.rb b/lib/enum_machine/version.rb
index 8c8bb34..171f209 100644
--- a/lib/enum_machine/version.rb
+++ b/lib/enum_machine/version.rb
@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
 module EnumMachine
-
   VERSION = "1.0.0"
-
 end
diff --git a/spec/enum_machine/active_record_enum_spec.rb b/spec/enum_machine/active_record_enum_spec.rb
index fd2daa8..66f8a50 100644
--- a/spec/enum_machine/active_record_enum_spec.rb
+++ b/spec/enum_machine/active_record_enum_spec.rb
@@ -34,11 +34,6 @@
     expect { m.color.wrong? }.to raise_error(NoMethodError)
   end
 
-  it "pretty print inspect" do
-    m = model.new(state: "choice")
-    expect(m.state.inspect).to match(/EnumMachine:BuildAttribute.+value=choice parent=/)
-  end
-
   it "test I18n" do
     I18n.load_path = Dir["#{File.expand_path('spec/locales')}/*.yml"]
     I18n.default_locale = :ru
@@ -83,6 +78,34 @@
     end
   end
 
+  context "when with decorator" do
+    let(:decorator_module) do
+      Module.new do
+        def am_i_choice?
+          self == "choice"
+        end
+      end
+    end
+
+    let(:model_with_decorator) do
+      decorator = decorator_module
+      Class.new(TestModel) do
+        enum_machine :state, %w[choice in_delivery], decorator: decorator
+      end
+    end
+
+    it "decorates enum value for new record" do
+      expect(model_with_decorator.new(state: "choice").state.am_i_choice?).to be(true)
+      expect(model_with_decorator.new(state: "in_delivery").state.am_i_choice?).to be(false)
+    end
+
+    it "decorates enum value for existing record" do
+      model_with_decorator.create(state: "choice")
+      m = model_with_decorator.find_by(state: "choice")
+      expect(m.state.am_i_choice?).to be(true)
+    end
+  end
+
   it "serialize model" do
     Object.const_set(:TestModelSerialize, model)
     m = TestModelSerialize.create(state: "choice", color: "wrong")
@@ -118,4 +141,11 @@
     expect(decorated_klass::STATE::CHOICE).to eq "choice"
     expect(decorated_klass::COLOR::RED).to eq "red"
   end
+
+  it "returns state value by []" do
+    expect(model::STATE["in_delivery"]).to eq "in_delivery"
+    expect(model::STATE["in_delivery"].in_delivery?).to be(true)
+    expect(model::STATE["in_delivery"].choice?).to be(false)
+    expect(model::STATE["wrong"]).to be_nil
+  end
 end
diff --git a/spec/enum_machine/driver_simple_class_spec.rb b/spec/enum_machine/driver_simple_class_spec.rb
index dfd13cb..66a7253 100644
--- a/spec/enum_machine/driver_simple_class_spec.rb
+++ b/spec/enum_machine/driver_simple_class_spec.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 class TestClass
-
   attr_accessor :state
 
   def initialize(state)
@@ -9,7 +8,22 @@ def initialize(state)
   end
 
   include EnumMachine[state: { enum: %w[choice in_delivery] }]
+end
 
+module Decorator
+  def am_i_choice?
+    self == "choice"
+  end
+end
+
+class TestClassWithDecorator
+  attr_accessor :state
+
+  def initialize(state)
+    @state = state
+  end
+
+  include EnumMachine[state: { enum: %w[choice in_delivery], decorator: Decorator }]
 end
 
 RSpec.describe "DriverSimpleClass" do
@@ -52,6 +66,33 @@ def initialize(state)
     end
   end
 
+  describe "TestClass::STATE const" do
+    it "#values" do
+      expect(TestClass::STATE.values).to eq(%w[choice in_delivery])
+    end
+
+    it "#[]" do
+      expect(TestClass::STATE["in_delivery"]).to eq "in_delivery"
+      expect(TestClass::STATE["in_delivery"].in_delivery?).to be(true)
+      expect(TestClass::STATE["in_delivery"].choice?).to be(false)
+      expect(TestClass::STATE["wrong"]).to be_nil
+    end
+
+    it "#decorator_module" do
+      decorated_klass =
+        Class.new do
+          include TestClass::STATE.decorator_module
+          attr_accessor :state
+        end
+
+      decorated_item = decorated_klass.new
+      decorated_item.state = "choice"
+
+      expect(decorated_item.state).to be_choice
+      expect(decorated_klass::STATE::CHOICE).to eq "choice"
+    end
+  end
+
   context "when definition order is changed" do
     let(:invert_definition_class) do
       Class.new do
@@ -70,6 +111,24 @@ def initialize(state)
     end
   end
 
+  context "when with decorator" do
+    it "decorates enum values" do
+      expect(TestClassWithDecorator.new("choice").state.am_i_choice?).to be(true)
+      expect(TestClassWithDecorator.new("in_delivery").state.am_i_choice?).to be(false)
+    end
+
+    it "decorates enum values in enum const" do
+      expect(TestClassWithDecorator::STATE.values.map(&:am_i_choice?)).to eq([true, false])
+      expect((TestClassWithDecorator::STATE.values & ["in_delivery"]).map(&:am_i_choice?)).to eq([false])
+    end
+
+    it "keeps decorating on serialization" do
+      m = TestClassWithDecorator.new("choice")
+      unserialized_m = Marshal.load(Marshal.dump(m)) # rubocop:disable Gp/UnsafeYamlMarshal
+      expect(unserialized_m.state.am_i_choice?).to be(true)
+    end
+  end
+
   it "serialize class" do
     m = TestClass.new("choice")
 
@@ -78,18 +137,4 @@ def initialize(state)
     expect(unserialized_m.state).to be_choice
     expect(unserialized_m.class::STATE::CHOICE).to eq "choice"
   end
-
-  it "test decorator" do
-    decorated_klass =
-      Class.new do
-        include TestClass::STATE.decorator_module
-        attr_accessor :state
-      end
-
-    decorated_item = decorated_klass.new
-    decorated_item.state = "choice"
-
-    expect(decorated_item.state).to be_choice
-    expect(decorated_klass::STATE::CHOICE).to eq "choice"
-  end
 end
diff --git a/spec/support/test_model.rb b/spec/support/test_model.rb
index c81d481..0b4a516 100644
--- a/spec/support/test_model.rb
+++ b/spec/support/test_model.rb
@@ -3,9 +3,7 @@
 require "active_record"
 
 class TestModel < ActiveRecord::Base
-
   def self.model_name
     ActiveModel::Name.new(self, nil, "test_model")
   end
-
 end
diff --git a/test/performance.rb b/test/performance.rb
index e842f7f..8206117 100644
--- a/test/performance.rb
+++ b/test/performance.rb
@@ -32,7 +32,6 @@
 STATES_IN_TRANSIT = %w[shipped delivered_to_office delivered_to_courier_city].freeze
 
 class OrderEnumMachine < ActiveRecord::Base
-
   self.table_name = :orders
 
   enum_machine :state, %w[
@@ -62,11 +61,9 @@ class OrderEnumMachine < ActiveRecord::Base
       %w[wait_shipment shipped part_obtain obtain overdue rejection searched] | STATES_IN_TRANSIT => "lost",
     )
   end
-
 end
 
 class OrderAasm < ActiveRecord::Base
-
   include AASM
 
   self.table_name = :orders
@@ -175,11 +172,9 @@ class OrderAasm < ActiveRecord::Base
       transitions from: %i[wait_shipment shipped part_obtain obtain overdue rejection searched] | STATES_IN_TRANSIT, to: :lost
     end
   end
-
 end
 
 class OrderStateMachines < ActiveRecord::Base
-
   self.table_name = :orders
 
   state_machine :state, initial: nil do
@@ -262,7 +257,6 @@ class OrderStateMachines < ActiveRecord::Base
       transition %w[wait_shipment shipped part_obtain obtain overdue rejection searched] | STATES_IN_TRANSIT => "lost"
     end
   end
-
 end
 
 def pp_title(name, stmt)