diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..fec5ab4
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,28 @@
+name: Ruby CI
+
+on:
+  push:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby-version: [3.1.0, 3.0.0, 2.7.5]
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up Ruby ${{ matrix.ruby-version }}
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+          bundler-cache: true
+
+      - name: Install dependencies
+        run: bundle install
+
+      - name: Run tests
+        run: bundle exec rake spec
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
new file mode 100644
index 0000000..c6b86f0
--- /dev/null
+++ b/.github/workflows/lint.yml
@@ -0,0 +1,17 @@
+name: Linting
+
+on:
+  push:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 3.0
+          bundler-cache: true
+      - run: bundle install
+      - name: Rubocop
+        run: bundle exec rake rubocop
diff --git a/.gitignore b/.gitignore
index 20bf1d5..9ddffcc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,10 +1,4 @@
-# File generated by script/bootstrap
-/.bundle/
-/bin
-/vendor/ruby
-/vendor/gems/
-/vendor/cache/ruby/
-
+*.gem
 *.rbc
 .bundle
 .config
@@ -17,6 +11,7 @@ spec/reports
 test/tmp
 test/version_tmp
 tmp
+vendor/cache
 
 Gemfile.lock
 out/
@@ -28,5 +23,8 @@ docs/
 # YARD artifacts
 .yardoc
 _yardoc
-doc/
+
 .DS_Store
+.idea
+.byebug_history
+.vscode
diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 0000000..08d42f3
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,6 @@
+inherit_gem:
+  rubocop-standard:
+    - config/default.yml
+
+Naming/FileName:
+  Enabled: false
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 3cc1286..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,18 +0,0 @@
-language: ruby
-script: "./script/cibuild"
-rvm:
-  - 2.4
-  - 2.5
-  - 2.6
-  - 2.7
-
-sudo: false
-cache: bundler
-
-notifications:
-  email:
-    on_success: never
-    on_failure: never
-
-git:
-  depth: 10
diff --git a/Gemfile b/Gemfile
index d65e2a6..f7200f1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'http://rubygems.org'
 
 gemspec
diff --git a/LICENSE b/LICENSE.txt
similarity index 100%
rename from LICENSE
rename to LICENSE.txt
diff --git a/README.md b/README.md
index 880f17d..b228c3f 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,5 @@
 # ecma-re-validator
 
-[![Build Status](https://travis-ci.org/gjtorikian/ecma-re-validator.svg?branch=master)](https://travis-ci.org/gjtorikian/ecma-re-validator)
-
 Pass in a string to validate if it would work in ECMA-262, aka JavaScript.
 
 The information for what is valid and what isn't comes from <http://www.regular-expressions.info/javascript.html>.
diff --git a/Rakefile b/Rakefile
index 72f3920..b438f3a 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'bundler'
 Bundler::GemHelper.install_tasks
 
@@ -5,4 +7,8 @@ require 'rspec/core/rake_task'
 
 RSpec::Core::RakeTask.new(:spec)
 
-task :default => [:spec]
+task default: [:spec]
+
+require 'rubocop/rake_task'
+
+RuboCop::RakeTask.new(:rubocop)
diff --git a/ecma-re-validator.gemspec b/ecma-re-validator.gemspec
index afcd03b..7d796a6 100644
--- a/ecma-re-validator.gemspec
+++ b/ecma-re-validator.gemspec
@@ -12,14 +12,19 @@ Gem::Specification.new do |gem|
   gem.summary       = %(Validate a regular expression string against what ECMA-262 can actually do.)
   gem.homepage      = 'https://github.com/gjtorikian/ecma-re-validator'
   gem.license       = 'MIT'
-  gem.files         = `git ls-files -z`.split("\x0").reject { |f| f =~ %r{^vendor/.*} }
+  gem.files         = `git ls-files -z`.split("\x0").grep_v(%r{^vendor/.*})
   gem.test_files    = gem.files.grep(%r{^(spec)/})
   gem.require_paths = ['lib']
+  gem.required_ruby_version = ['>= 2.6.0', '< 4.0']
 
   gem.add_dependency 'regexp_parser', '~> 2.2'
 
-  gem.add_development_dependency 'rspec', '~> 3.1'
-  gem.add_development_dependency 'rake', '~> 13.0'
   gem.add_development_dependency 'awesome_print'
-  gem.add_development_dependency 'pry', '~> 0.10'
+  gem.add_development_dependency 'rake', '~> 13.0'
+  gem.add_development_dependency 'rspec', '~> 3.1'
+
+  gem.add_development_dependency 'rubocop'
+  gem.add_development_dependency 'rubocop-rspec'
+  gem.add_development_dependency 'rubocop-standard'
+  gem.metadata['rubygems_mfa_required'] = 'true'
 end
diff --git a/lib/ecma-re-validator.rb b/lib/ecma-re-validator.rb
index c6242fb..08c6238 100644
--- a/lib/ecma-re-validator.rb
+++ b/lib/ecma-re-validator.rb
@@ -1,12 +1,8 @@
-begin
-  require 'awesome_print'
-  require 'pry'
-rescue LoadError; end
+# frozen_string_literal: true
 
 require 'regexp_parser'
 
 module EcmaReValidator
-
   # JS doesn't have Unicode matching
   UNICODE_CHARACTERS = Regexp::Syntax::Token::UnicodeProperty::All
 
@@ -27,7 +23,7 @@ module EcmaReValidator
     :condition_open,
     # JS doesn't support comments
     :comment
-  ]
+  ].freeze
 
   INVALID_TOKENS = INVALID_REGEXP + UNICODE_CHARACTERS
 
diff --git a/spec/anchors_spec.rb b/spec/anchors_spec.rb
index d8429e4..5992a79 100644
--- a/spec/anchors_spec.rb
+++ b/spec/anchors_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaReValidator::Anchors' do
diff --git a/spec/atomic_grouping_spec.rb b/spec/atomic_grouping_spec.rb
index c8c7f58..be4bf7c 100644
--- a/spec/atomic_grouping_spec.rb
+++ b/spec/atomic_grouping_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaReValidator::AtomicGrouping' do
diff --git a/spec/comments_spec.rb b/spec/comments_spec.rb
index f9149f5..182dd97 100644
--- a/spec/comments_spec.rb
+++ b/spec/comments_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaReValidator::Comments' do
@@ -8,15 +10,14 @@
   end
 
   it 'should fail if regexp has inline comments across lines' do
-    re = %r{
+    re = /
           start         # some text
           \s            # white space char
           (group)       # first group
           (?:alt1|alt2) # some alternation
           end
-        }x
+        /x
 
     expect(EcmaReValidator.valid?(re)).to eql(false)
   end
-
 end
diff --git a/spec/conditionals_spec.rb b/spec/conditionals_spec.rb
index 57746e3..4c5b27d 100644
--- a/spec/conditionals_spec.rb
+++ b/spec/conditionals_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaReValidator::Conditionals' do
diff --git a/spec/lookbehind_spec.rb b/spec/lookbehind_spec.rb
index 9dc89f6..7a7dd95 100644
--- a/spec/lookbehind_spec.rb
+++ b/spec/lookbehind_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaReValidator::Lookbehind' do
diff --git a/spec/mode_modifiers_spec.rb b/spec/mode_modifiers_spec.rb
index fc1f543..f1fa269 100644
--- a/spec/mode_modifiers_spec.rb
+++ b/spec/mode_modifiers_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaReValidator::ModeModifiers' do
diff --git a/spec/named_capture_groups_spec.rb b/spec/named_capture_groups_spec.rb
index 39beb61..3e3c53d 100644
--- a/spec/named_capture_groups_spec.rb
+++ b/spec/named_capture_groups_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaReValidator::NamedCaptureGroups' do
diff --git a/spec/possesive_quantifiers_spec.rb b/spec/possesive_quantifiers_spec.rb
index 2d3dd80..48f031d 100644
--- a/spec/possesive_quantifiers_spec.rb
+++ b/spec/possesive_quantifiers_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaReValidator::PossesiveQuantifiers' do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index f155b43..7526b75 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 require 'bundler/setup'
-require_relative "../lib/ecma-re-validator"
+require_relative '../lib/ecma-re-validator'
 
 RSpec.configure do |config|
   # Use color in STDOUT
diff --git a/spec/unicode_spec.rb b/spec/unicode_spec.rb
index d7ac9ea..32dd769 100644
--- a/spec/unicode_spec.rb
+++ b/spec/unicode_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaReValidator::Unicode' do
diff --git a/spec/validator_spec.rb b/spec/validator_spec.rb
index 38d0ed6..068854a 100644
--- a/spec/validator_spec.rb
+++ b/spec/validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe 'EcmaRe' do
@@ -14,7 +16,7 @@
   end
 
   it 'passes for a valid regexp string' do
-    re = "[Ss]mith\\\\b"
+    re = '[Ss]mith\\\\b'
 
     expect(EcmaReValidator.valid?(re)).to eql(true)
   end
diff --git a/vendor/cache/coderay-1.1.3.gem b/vendor/cache/coderay-1.1.3.gem
deleted file mode 100644
index 3475820..0000000
Binary files a/vendor/cache/coderay-1.1.3.gem and /dev/null differ
diff --git a/vendor/cache/method_source-1.0.0.gem b/vendor/cache/method_source-1.0.0.gem
deleted file mode 100644
index 2e035c3..0000000
Binary files a/vendor/cache/method_source-1.0.0.gem and /dev/null differ
diff --git a/vendor/cache/rspec-3.10.0.gem b/vendor/cache/rspec-3.10.0.gem
deleted file mode 100644
index 8932c9c..0000000
Binary files a/vendor/cache/rspec-3.10.0.gem and /dev/null differ