diff --git a/Gemfile b/Gemfile
index 84a9fad..f24d66f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,3 +2,13 @@ source 'https://rubygems.org'
 
 # Specify gem dependencies in the .gemspec file
 gemspec
+
+# Development dependencies
+gem 'bundler'
+gem 'rake'
+gem 'minitest'
+gem 'minitest-reporters'
+gem 'colorize'
+gem 'rubocop', '1.24.1'
+gem 'pry'
+gem 'simplecov', '0.21.2'
diff --git a/Rakefile b/Rakefile
index fde72bf..881c20b 100644
--- a/Rakefile
+++ b/Rakefile
@@ -19,15 +19,6 @@ task :gemspec do
     # behavior of that as in version 5 of ActiveSupport.
     spec.add_dependency 'activesupport', '>= 4.0'
     spec.add_dependency 'ruby2_keywords', '>= 0.0.4'
-    spec.add_development_dependency 'bundler'
-    spec.add_development_dependency 'rake'
-    spec.add_development_dependency 'minitest'
-    spec.add_development_dependency 'minitest-reporters'
-    spec.add_development_dependency 'colorize'
-    spec.add_development_dependency 'rubocop', '1.24.1'
-    spec.add_development_dependency 'pry'
-    spec.add_development_dependency 'byebug'
-    spec.add_development_dependency 'simplecov', '0.21.2'
   end
 
   File.write('schemacop.gemspec', gemspec.to_ruby.strip)
diff --git a/schemacop.gemspec b/schemacop.gemspec
index f184d2b..79d46d1 100644
--- a/schemacop.gemspec
+++ b/schemacop.gemspec
@@ -3,30 +3,31 @@
 
 Gem::Specification.new do |s|
   s.name = "schemacop".freeze
-  s.version = "3.0.28".freeze
+  s.version = "3.0.28"
 
   s.required_rubygems_version = Gem::Requirement.new(">= 0".freeze) if s.respond_to? :required_rubygems_version=
   s.require_paths = ["lib".freeze]
   s.authors = ["Sitrox".freeze]
-  s.date = "2023-12-20"
+  s.date = "2024-06-06"
   s.files = [".github/workflows/ruby.yml".freeze, ".gitignore".freeze, ".releaser_config".freeze, ".rubocop.yml".freeze, ".yardopts".freeze, "CHANGELOG.md".freeze, "Gemfile".freeze, "LICENSE".freeze, "README.md".freeze, "README_V2.md".freeze, "README_V3.md".freeze, "RUBY_VERSION".freeze, "Rakefile".freeze, "VERSION".freeze, "lib/schemacop.rb".freeze, "lib/schemacop/base_schema.rb".freeze, "lib/schemacop/exceptions.rb".freeze, "lib/schemacop/railtie.rb".freeze, "lib/schemacop/schema.rb".freeze, "lib/schemacop/schema2.rb".freeze, "lib/schemacop/schema3.rb".freeze, "lib/schemacop/scoped_env.rb".freeze, "lib/schemacop/v2.rb".freeze, "lib/schemacop/v2/caster.rb".freeze, "lib/schemacop/v2/collector.rb".freeze, "lib/schemacop/v2/dupper.rb".freeze, "lib/schemacop/v2/field_node.rb".freeze, "lib/schemacop/v2/node.rb".freeze, "lib/schemacop/v2/node_resolver.rb".freeze, "lib/schemacop/v2/node_supporting_field.rb".freeze, "lib/schemacop/v2/node_supporting_type.rb".freeze, "lib/schemacop/v2/node_with_block.rb".freeze, "lib/schemacop/v2/validator/array_validator.rb".freeze, "lib/schemacop/v2/validator/boolean_validator.rb".freeze, "lib/schemacop/v2/validator/float_validator.rb".freeze, "lib/schemacop/v2/validator/hash_validator.rb".freeze, "lib/schemacop/v2/validator/integer_validator.rb".freeze, "lib/schemacop/v2/validator/nil_validator.rb".freeze, "lib/schemacop/v2/validator/number_validator.rb".freeze, "lib/schemacop/v2/validator/object_validator.rb".freeze, "lib/schemacop/v2/validator/string_validator.rb".freeze, "lib/schemacop/v2/validator/symbol_validator.rb".freeze, "lib/schemacop/v3.rb".freeze, "lib/schemacop/v3/all_of_node.rb".freeze, "lib/schemacop/v3/any_of_node.rb".freeze, "lib/schemacop/v3/array_node.rb".freeze, "lib/schemacop/v3/boolean_node.rb".freeze, "lib/schemacop/v3/combination_node.rb".freeze, "lib/schemacop/v3/context.rb".freeze, "lib/schemacop/v3/dsl_scope.rb".freeze, "lib/schemacop/v3/global_context.rb".freeze, "lib/schemacop/v3/hash_node.rb".freeze, "lib/schemacop/v3/integer_node.rb".freeze, "lib/schemacop/v3/is_not_node.rb".freeze, "lib/schemacop/v3/node.rb".freeze, "lib/schemacop/v3/node_registry.rb".freeze, "lib/schemacop/v3/number_node.rb".freeze, "lib/schemacop/v3/numeric_node.rb".freeze, "lib/schemacop/v3/object_node.rb".freeze, "lib/schemacop/v3/one_of_node.rb".freeze, "lib/schemacop/v3/reference_node.rb".freeze, "lib/schemacop/v3/result.rb".freeze, "lib/schemacop/v3/string_node.rb".freeze, "lib/schemacop/v3/symbol_node.rb".freeze, "schemacop.gemspec".freeze, "test/lib/test_helper.rb".freeze, "test/schemas/nested/group.rb".freeze, "test/schemas/user.rb".freeze, "test/unit/schemacop/v2/casting_test.rb".freeze, "test/unit/schemacop/v2/collector_test.rb".freeze, "test/unit/schemacop/v2/custom_check_test.rb".freeze, "test/unit/schemacop/v2/custom_if_test.rb".freeze, "test/unit/schemacop/v2/defaults_test.rb".freeze, "test/unit/schemacop/v2/empty_test.rb".freeze, "test/unit/schemacop/v2/nil_dis_allow_test.rb".freeze, "test/unit/schemacop/v2/node_resolver_test.rb".freeze, "test/unit/schemacop/v2/short_forms_test.rb".freeze, "test/unit/schemacop/v2/types_test.rb".freeze, "test/unit/schemacop/v2/validator_array_test.rb".freeze, "test/unit/schemacop/v2/validator_boolean_test.rb".freeze, "test/unit/schemacop/v2/validator_float_test.rb".freeze, "test/unit/schemacop/v2/validator_hash_test.rb".freeze, "test/unit/schemacop/v2/validator_integer_test.rb".freeze, "test/unit/schemacop/v2/validator_nil_test.rb".freeze, "test/unit/schemacop/v2/validator_number_test.rb".freeze, "test/unit/schemacop/v2/validator_object_test.rb".freeze, "test/unit/schemacop/v2/validator_string_test.rb".freeze, "test/unit/schemacop/v2/validator_symbol_test.rb".freeze, "test/unit/schemacop/v3/all_of_node_test.rb".freeze, "test/unit/schemacop/v3/any_of_node_test.rb".freeze, "test/unit/schemacop/v3/array_node_test.rb".freeze, "test/unit/schemacop/v3/boolean_node_test.rb".freeze, "test/unit/schemacop/v3/global_context_test.rb".freeze, "test/unit/schemacop/v3/hash_node_test.rb".freeze, "test/unit/schemacop/v3/integer_node_test.rb".freeze, "test/unit/schemacop/v3/is_not_node_test.rb".freeze, "test/unit/schemacop/v3/node_test.rb".freeze, "test/unit/schemacop/v3/number_node_test.rb".freeze, "test/unit/schemacop/v3/object_node_test.rb".freeze, "test/unit/schemacop/v3/one_of_node_test.rb".freeze, "test/unit/schemacop/v3/reference_node_test.rb".freeze, "test/unit/schemacop/v3/string_node_test.rb".freeze, "test/unit/schemacop/v3/symbol_node_test.rb".freeze]
   s.homepage = "https://github.com/sitrox/schemacop".freeze
   s.licenses = ["MIT".freeze]
-  s.rubygems_version = "3.4.22".freeze
+  s.rubygems_version = "3.0.3".freeze
   s.summary = "Schemacop validates ruby structures consisting of nested hashes and arrays against simple schema definitions.".freeze
   s.test_files = ["test/lib/test_helper.rb".freeze, "test/schemas/nested/group.rb".freeze, "test/schemas/user.rb".freeze, "test/unit/schemacop/v2/casting_test.rb".freeze, "test/unit/schemacop/v2/collector_test.rb".freeze, "test/unit/schemacop/v2/custom_check_test.rb".freeze, "test/unit/schemacop/v2/custom_if_test.rb".freeze, "test/unit/schemacop/v2/defaults_test.rb".freeze, "test/unit/schemacop/v2/empty_test.rb".freeze, "test/unit/schemacop/v2/nil_dis_allow_test.rb".freeze, "test/unit/schemacop/v2/node_resolver_test.rb".freeze, "test/unit/schemacop/v2/short_forms_test.rb".freeze, "test/unit/schemacop/v2/types_test.rb".freeze, "test/unit/schemacop/v2/validator_array_test.rb".freeze, "test/unit/schemacop/v2/validator_boolean_test.rb".freeze, "test/unit/schemacop/v2/validator_float_test.rb".freeze, "test/unit/schemacop/v2/validator_hash_test.rb".freeze, "test/unit/schemacop/v2/validator_integer_test.rb".freeze, "test/unit/schemacop/v2/validator_nil_test.rb".freeze, "test/unit/schemacop/v2/validator_number_test.rb".freeze, "test/unit/schemacop/v2/validator_object_test.rb".freeze, "test/unit/schemacop/v2/validator_string_test.rb".freeze, "test/unit/schemacop/v2/validator_symbol_test.rb".freeze, "test/unit/schemacop/v3/all_of_node_test.rb".freeze, "test/unit/schemacop/v3/any_of_node_test.rb".freeze, "test/unit/schemacop/v3/array_node_test.rb".freeze, "test/unit/schemacop/v3/boolean_node_test.rb".freeze, "test/unit/schemacop/v3/global_context_test.rb".freeze, "test/unit/schemacop/v3/hash_node_test.rb".freeze, "test/unit/schemacop/v3/integer_node_test.rb".freeze, "test/unit/schemacop/v3/is_not_node_test.rb".freeze, "test/unit/schemacop/v3/node_test.rb".freeze, "test/unit/schemacop/v3/number_node_test.rb".freeze, "test/unit/schemacop/v3/object_node_test.rb".freeze, "test/unit/schemacop/v3/one_of_node_test.rb".freeze, "test/unit/schemacop/v3/reference_node_test.rb".freeze, "test/unit/schemacop/v3/string_node_test.rb".freeze, "test/unit/schemacop/v3/symbol_node_test.rb".freeze]
 
-  s.specification_version = 4
+  if s.respond_to? :specification_version then
+    s.specification_version = 4
 
-  s.add_runtime_dependency(%q<activesupport>.freeze, [">= 4.0".freeze])
-  s.add_runtime_dependency(%q<ruby2_keywords>.freeze, [">= 0.0.4".freeze])
-  s.add_development_dependency(%q<bundler>.freeze, [">= 0".freeze])
-  s.add_development_dependency(%q<rake>.freeze, [">= 0".freeze])
-  s.add_development_dependency(%q<minitest>.freeze, [">= 0".freeze])
-  s.add_development_dependency(%q<minitest-reporters>.freeze, [">= 0".freeze])
-  s.add_development_dependency(%q<colorize>.freeze, [">= 0".freeze])
-  s.add_development_dependency(%q<rubocop>.freeze, ["= 1.24.1".freeze])
-  s.add_development_dependency(%q<pry>.freeze, [">= 0".freeze])
-  s.add_development_dependency(%q<byebug>.freeze, [">= 0".freeze])
-  s.add_development_dependency(%q<simplecov>.freeze, ["= 0.21.2".freeze])
+    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.2.0') then
+      s.add_runtime_dependency(%q<activesupport>.freeze, [">= 4.0"])
+      s.add_runtime_dependency(%q<ruby2_keywords>.freeze, [">= 0.0.4"])
+    else
+      s.add_dependency(%q<activesupport>.freeze, [">= 4.0"])
+      s.add_dependency(%q<ruby2_keywords>.freeze, [">= 0.0.4"])
+    end
+  else
+    s.add_dependency(%q<activesupport>.freeze, [">= 4.0"])
+    s.add_dependency(%q<ruby2_keywords>.freeze, [">= 0.0.4"])
+  end
 end
\ No newline at end of file