diff --git a/Gemfile b/Gemfile
index 507491c..a3d355a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,6 +2,7 @@ source "https://rubygems.org"
 
 gem "pry", "~> 0.14"
 gem "rspec", "~> 3.11"
+gem "activesupport", "~> 7.0.4"
 gem "rubocop-shopify"
 gem "rubocop-rspec"
 gem "rubocop"
diff --git a/Gemfile.lock b/Gemfile.lock
index 07380f1..99b79fa 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,11 +1,20 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    activesupport (7.0.4)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 1.6, < 2)
+      minitest (>= 5.1)
+      tzinfo (~> 2.0)
     ast (2.4.2)
     coderay (1.1.3)
+    concurrent-ruby (1.1.10)
     diff-lcs (1.5.0)
+    i18n (1.12.0)
+      concurrent-ruby (~> 1.0)
     json (2.6.2)
     method_source (1.0.0)
+    minitest (5.16.3)
     parallel (1.22.1)
     parser (3.1.2.1)
       ast (~> 2.4.1)
@@ -51,6 +60,8 @@ GEM
     ruby2_keywords (0.0.5)
     saharspec (0.0.9)
       ruby2_keywords
+    tzinfo (2.0.5)
+      concurrent-ruby (~> 1.0)
     unicode-display_width (2.3.0)
 
 PLATFORMS
@@ -58,6 +69,7 @@ PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
+  activesupport (~> 7.0.4)
   pry (~> 0.14)
   rspec (~> 3.11)
   rspec-its
diff --git a/VERSION b/VERSION
index f905682..8f0916f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.4.7
+0.5.0
diff --git a/lib/core_ext.rb b/lib/core_ext.rb
deleted file mode 100644
index 306a182..0000000
--- a/lib/core_ext.rb
+++ /dev/null
@@ -1,2 +0,0 @@
-require "core_ext/deep_dup"
-require "core_ext/duplicable"
diff --git a/lib/core_ext/deep_dup.rb b/lib/core_ext/deep_dup.rb
deleted file mode 100644
index b0a3758..0000000
--- a/lib/core_ext/deep_dup.rb
+++ /dev/null
@@ -1,53 +0,0 @@
-# https://github.com/rails/rails/blob/main/activesupport/lib/active_support/core_ext/object/deep_dup.rb
-
-class Object
-  # Returns a deep copy of object if it's duplicable. If it's
-  # not duplicable, returns +self+.
-  #
-  #   object = Object.new
-  #   dup    = object.deep_dup
-  #   dup.instance_variable_set(:@a, 1)
-  #
-  #   object.instance_variable_defined?(:@a) # => false
-  #   dup.instance_variable_defined?(:@a)    # => true
-  def deep_dup
-    duplicable? ? dup : self
-  end
-end
-
-class Array
-  # Returns a deep copy of array.
-  #
-  #   array = [1, [2, 3]]
-  #   dup   = array.deep_dup
-  #   dup[1][2] = 4
-  #
-  #   array[1][2] # => nil
-  #   dup[1][2]   # => 4
-  def deep_dup
-    map(&:deep_dup)
-  end
-end
-
-class Hash
-  # Returns a deep copy of hash.
-  #
-  #   hash = { a: { b: 'b' } }
-  #   dup  = hash.deep_dup
-  #   dup[:a][:c] = 'c'
-  #
-  #   hash[:a][:c] # => nil
-  #   dup[:a][:c]  # => "c"
-  def deep_dup
-    hash = dup
-    each_pair do |key, value|
-      if ::String === key || ::Symbol === key
-        hash[key] = value.deep_dup
-      else
-        hash.delete(key)
-        hash[key.deep_dup] = value.deep_dup
-      end
-    end
-    hash
-  end
-end
diff --git a/lib/core_ext/duplicable.rb b/lib/core_ext/duplicable.rb
deleted file mode 100644
index b60cdc6..0000000
--- a/lib/core_ext/duplicable.rb
+++ /dev/null
@@ -1,42 +0,0 @@
-# https://github.com/rails/rails/blob/main/activesupport/lib/active_support/core_ext/object/duplicable.rb
-
-class Object
-  # Can you safely dup this object?
-  #
-  # False for method objects;
-  # true otherwise.
-  def duplicable?
-    true
-  end
-end
-
-class Method
-  # Methods are not duplicable:
-  #
-  #   method(:puts).duplicable? # => false
-  #   method(:puts).dup         # => TypeError: allocator undefined for Method
-  def duplicable?
-    false
-  end
-end
-
-class UnboundMethod
-  # Unbound methods are not duplicable:
-  #
-  #   method(:puts).unbind.duplicable? # => false
-  #   method(:puts).unbind.dup         # => TypeError: allocator undefined for UnboundMethod
-  def duplicable?
-    false
-  end
-end
-
-require "singleton"
-
-module Singleton
-  # Singleton instances are not duplicable:
-  #
-  #   Class.new.include(Singleton).instance.dup # TypeError (can't dup instance of singleton
-  def duplicable?
-    false
-  end
-end
diff --git a/lib/statinize.rb b/lib/statinize.rb
index ca66b99..79c47f0 100644
--- a/lib/statinize.rb
+++ b/lib/statinize.rb
@@ -1,7 +1,9 @@
 require "set"
 require "pry"
+require "active_support"
+require "active_support/core_ext/object/deep_dup"
+require "active_support/core_ext/object/with_options"
 require "bigdecimal/util"
-require "core_ext"
 require "statinize/statinizable"
 require "statinize/dsl"
 require "statinize/statinizer"
diff --git a/lib/statinize/dsl.rb b/lib/statinize/dsl.rb
index a042bbd..8c820df 100644
--- a/lib/statinize/dsl.rb
+++ b/lib/statinize/dsl.rb
@@ -1,6 +1,8 @@
 # Defines DSL for statinize block
 module Statinize
   module DSL
+    alias_method :with, :with_options
+
     def attribute(*attrs, **options)
       attrs.each do |attr|
         Attribute.create(klass, attr, options) unless attribute? attr
@@ -15,26 +17,6 @@ def validate(*attrs, **options)
       end
     end
 
-    def with(**options, &block)
-      # create new statinizer instance
-      instance = self.class.new(klass)
-      instance.force(force)
-
-      # execute block in the context of that statinizer
-      # while it's attached to the klass
-      # then rewind and attach the original statinizer(self)
-      # back to the klass
-      klass.instance_variable_set(:@statinizer, instance)
-      instance.instance_exec(&block)
-      klass.instance_variable_set(:@statinizer, self)
-
-      # merge the newly created statinizer with the options
-      instance.merge_options(**options)
-
-      # populate self with the instance's attributes
-      populate(instance.attributes)
-    end
-
     def before(&block)
       return unless block_given?
 
diff --git a/lib/statinize/statinizer.rb b/lib/statinize/statinizer.rb
index e1b6833..8a86c7c 100644
--- a/lib/statinize/statinizer.rb
+++ b/lib/statinize/statinizer.rb
@@ -40,14 +40,6 @@ def check_validators_exist!
       raise NoSuchValidatorError unless all_validators_defined?
     end
 
-    def merge_options(**options)
-      attributes.each do |attribute|
-        attribute.options_collection.each do |option|
-          option.merge!(options)
-        end
-      end
-    end
-
     def populate(attrs)
       attrs.each do |attr|
         attribute attr.arg_name, name: attr.name, default: attr.default, default_exec: attr.default_exec
diff --git a/spec/statinize/with_spec.rb b/spec/statinize/with_spec.rb
new file mode 100644
index 0000000..0a6aaaf
--- /dev/null
+++ b/spec/statinize/with_spec.rb
@@ -0,0 +1,40 @@
+RSpec.describe "With" do
+  subject { WithDummy.new(params) }
+
+  context "two with blocks" do
+    context "first validation is violated" do
+      let!(:params) { { a: "a", c: :a } }
+
+      its(:valid?) { should be_truthy }
+
+      context "both validations are calls to validate" do
+        let!(:params) { { a: :a, c: "c" } }
+
+        its(:valid?) { should be_falsey }
+      end
+    end
+  end
+end
+
+class WithDummy
+  include Statinize
+
+  statinize do
+    with type: Symbol do
+      attribute :a
+    end
+
+    with presence: true do
+      attribute :a
+    end
+
+    attribute :c
+    with type: Symbol do
+      validate :c
+    end
+
+    with presence: true do
+      validate :c
+    end
+  end
+end
diff --git a/statinize.gemspec b/statinize.gemspec
index 70a959c..4aa14e7 100644
--- a/statinize.gemspec
+++ b/statinize.gemspec
@@ -10,4 +10,6 @@ Gem::Specification.new do |s|
   s.files       = Dir["lib/**/*.rb"]
   s.license     = "MIT"
   s.platform    = Gem::Platform::RUBY
+
+  s.add_runtime_dependency "activesupport", "~> 7.0.0"
 end