diff --git a/Gemfile b/Gemfile
index fffa200..1841665 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 gemspec
diff --git a/README.md b/README.md
index d402b23..750e4d0 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,8 @@
 # Errbit Github Plugin
 
+[![RSpec](https://github.com/errbit/errbit_github_plugin/actions/workflows/rspec.yml/badge.svg)](https://github.com/errbit/errbit_github_plugin/actions/workflows/rspec.yml)
+[![RSpec on JRuby](https://github.com/errbit/errbit_github_plugin/actions/workflows/jruby.yml/badge.svg)](https://github.com/errbit/errbit_github_plugin/actions/workflows/jruby.yml)
+[![Ruby Style Guide](https://img.shields.io/badge/code_style-standard-brightgreen.svg)](https://github.com/standardrb/standard)
+
 This plugin provides GitHub issue tracker integration for Errbit and it is the
 only plugin included by default in Errbit.
diff --git a/Rakefile b/Rakefile
index 2995527..5263b58 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 require "bundler/gem_tasks"
diff --git a/errbit_github_plugin.gemspec b/errbit_github_plugin.gemspec
index ff4d35b..413739f 100644
--- a/errbit_github_plugin.gemspec
+++ b/errbit_github_plugin.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 lib = File.expand_path('../lib', __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'errbit_github_plugin/version'
diff --git a/lib/errbit_github_plugin.rb b/lib/errbit_github_plugin.rb
index fcddc1e..0ae96cb 100644
--- a/lib/errbit_github_plugin.rb
+++ b/lib/errbit_github_plugin.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "errbit_github_plugin/version"
 require 'errbit_github_plugin/error'
 require 'errbit_github_plugin/issue_tracker'
diff --git a/lib/errbit_github_plugin/error.rb b/lib/errbit_github_plugin/error.rb
index dc8859f..655dbf6 100644
--- a/lib/errbit_github_plugin/error.rb
+++ b/lib/errbit_github_plugin/error.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ErrbitGithubPlugin
   class AuthenticationError < Exception; end
 end
diff --git a/lib/errbit_github_plugin/issue_tracker.rb b/lib/errbit_github_plugin/issue_tracker.rb
index 3587972..c514e84 100644
--- a/lib/errbit_github_plugin/issue_tracker.rb
+++ b/lib/errbit_github_plugin/issue_tracker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'octokit'
 
 module ErrbitGithubPlugin
@@ -5,10 +7,10 @@ class IssueTracker < ErrbitPlugin::IssueTracker
 
     LABEL = 'github'
 
-    NOTE = 'Please configure your github repository in the <strong>GITHUB ' <<
-           'REPO</strong> field above.<br/> Instead of providing your ' <<
-           'username & password, you can link your Github account to your ' <<
-           'user profile, and allow Errbit to create issues using your ' <<
+    NOTE = 'Please configure your github repository in the <strong>GITHUB ' \
+           'REPO</strong> field above.<br/> Instead of providing your ' \
+           'username & password, you can link your Github account to your ' \
+           'user profile, and allow Errbit to create issues using your ' \
            'OAuth token.'
 
     FIELDS = {
diff --git a/lib/errbit_github_plugin/version.rb b/lib/errbit_github_plugin/version.rb
index 5784dc0..6045bea 100644
--- a/lib/errbit_github_plugin/version.rb
+++ b/lib/errbit_github_plugin/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ErrbitGithubPlugin
   VERSION = '0.4.0'
 end
diff --git a/spec/issue_tracker_spec.rb b/spec/issue_tracker_spec.rb
index 22dd275..61fa658 100644
--- a/spec/issue_tracker_spec.rb
+++ b/spec/issue_tracker_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe ErrbitGithubPlugin::IssueTracker do
   describe '.label' do
     it 'return LABEL' do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 03f785b..5daef9a 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'simplecov'
 
 SimpleCov.start