diff --git a/.github/workflows/ruby.yaml b/.github/workflows/ruby.yaml
new file mode 100644
index 0000000..dbe3313
--- /dev/null
+++ b/.github/workflows/ruby.yaml
@@ -0,0 +1,28 @@
+name: Ruby CI
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        ruby-version: ["3.2", "3.1", "3.0", "2.7", "2.6"]
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Ruby ${{ matrix.ruby-version }}
+        uses: ruby/setup-ruby@v1.134.0
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+      - name: Install dependencies
+        run: bundle install
+      - name: Run tests
+        run: bundle exec rake
+      - name: rubocop
+        run: bundle exec rubocop
diff --git a/.rubocop.yml b/.rubocop.yml
index 9045fdc..0ebf1a8 100755
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,3 +1,8 @@
+AllCops:
+  TargetRubyVersion: "2.6"
+  Exclude:
+    - "benchmark/**/*"
+    - "tmp/**/*"
 StringLiterals:
   Enabled: false
   SupportedStyles:
@@ -6,3 +11,5 @@ StringLiterals:
 LineLength:
   Enabled: true
   Max: 100
+Style/AccessModifierDeclarations:
+  Enabled: false
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 995f716..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-language: ruby
-rvm:
-  - "2.0.0-p648"
-  - "2.1.10"
-  - "2.2.9"
-  - "2.3.6"
-  - "2.4.3"
-  - "2.5.0"
-script:
-  - bundle exec rake
-  - bundle exec rubocop
diff --git a/Gemfile b/Gemfile
index e777066..99607f3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 # Specify your gem's dependencies in ipconverter.gemspec
diff --git a/Rakefile b/Rakefile
index 3f3d881..7f9c868 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 require 'bundler/gem_tasks'
 require 'rake/testtask'
 require 'rake/extensiontask'
 
-ROOT = File.expand_path('..', __FILE__)
+ROOT = File.expand_path(__dir__)
 
 Rake::TestTask.new do |t|
   t.libs << 'test'
@@ -10,7 +12,7 @@ Rake::TestTask.new do |t|
 end
 
 Rake::ExtensionTask.new 'ipconverter' do |ext|
-  ext.lib_dir = 'lib/ipconverter'
+  ext.lib_dir = File.join %w[lib ipconverter]
 end
 
 task default: %i[compile test]
diff --git a/benchmark/int_to_str.rb b/benchmark/int_to_str.rb
index 40428f2..8072d3f 100755
--- a/benchmark/int_to_str.rb
+++ b/benchmark/int_to_str.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'benchmark'
 require 'ipaddr'
 require 'ipconverter'
diff --git a/benchmark/str_to_int.rb b/benchmark/str_to_int.rb
index 73e8e0c..b83216e 100755
--- a/benchmark/str_to_int.rb
+++ b/benchmark/str_to_int.rb
@@ -1,12 +1,13 @@
+# frozen_string_literal: true
+
 require 'benchmark'
 require 'ipaddr'
 require 'ipconverter'
 
 def self.pack_unpack(ip)
-  ip.split('.').collect(&:to_i).pack('C*').unpack('N').first
+  ip.split('.').collect(&:to_i).pack('C*').unpack1('N')
 end
 
-# rubocop:disable AbcSize
 def self.split_multiply(ip)
   octets = ip.split('.').map(&:to_i)
   octets[3] +
@@ -14,7 +15,6 @@ def self.split_multiply(ip)
     octets[1] * 256 * 256 +
     octets[0] * 256 * 256 * 256
 end
-# rubocop:enable AbcSize
 
 def self.ipaddr_to_i(ip)
   IPAddr.new(ip).to_i
diff --git a/ext/ipconverter/extconf.rb b/ext/ipconverter/extconf.rb
index b9f1697..c7fc9ba 100644
--- a/ext/ipconverter/extconf.rb
+++ b/ext/ipconverter/extconf.rb
@@ -1,4 +1,6 @@
+# frozen_string_literal: true
+
 require 'mkmf'
 extension_name = 'ipconverter'
 dir_config(extension_name)
-create_makefile(extension_name)
+create_makefile("ipconverter/ipconverter")
diff --git a/ipconverter.gemspec b/ipconverter.gemspec
index 7425e48..04f7ec3 100644
--- a/ipconverter.gemspec
+++ b/ipconverter.gemspec
@@ -1,6 +1,7 @@
+# frozen_string_literal: true
 
-lib = File.expand_path('../lib', __FILE__)
-ext = File.expand_path('../ext', __FILE__)
+lib = File.expand_path('lib', __dir__)
+ext = File.expand_path('ext', __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 $LOAD_PATH.unshift(ext) unless $LOAD_PATH.include?(ext)
 require 'ipconverter/version'
@@ -16,15 +17,17 @@ string to integer'
   spec.homepage      = 'http://github.com/joshuawscott/ipconverter'
   spec.license       = 'MIT'
 
+  spec.required_ruby_version = ">= 2.6.0"
+
   spec.files         = `git ls-files -z`.split("\x0")
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.extensions    = ['ext/ipconverter/extconf.rb']
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = %w[lib ext]
 
-  spec.add_development_dependency 'bundler', '~> 1.6'
+  spec.add_development_dependency 'bundler'
   spec.add_development_dependency 'minitest', '~> 5'
-  spec.add_development_dependency 'rake', '~> 12.3'
+  spec.add_development_dependency 'rake', '~> 13.0'
   spec.add_development_dependency 'rake-compiler', '~> 1.0'
   spec.add_development_dependency 'rubocop', '~> 0.50'
 end
diff --git a/lib/ipconverter.rb b/lib/ipconverter.rb
index ed637e7..e9a4da2 100644
--- a/lib/ipconverter.rb
+++ b/lib/ipconverter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'ipconverter/version'
 require 'ipconverter/ipconverter'
 
diff --git a/lib/ipconverter/version.rb b/lib/ipconverter/version.rb
index 671e012..a84d636 100644
--- a/lib/ipconverter/version.rb
+++ b/lib/ipconverter/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module IpConverter
-  VERSION = '0.3.1'.freeze
+  VERSION = '0.4.0'
 end
diff --git a/test/test_ipconverter.rb b/test/test_ipconverter.rb
index 5ad049c..a2102dc 100644
--- a/test/test_ipconverter.rb
+++ b/test/test_ipconverter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'ipconverter'
 require 'minitest/autorun'