diff --git a/.rubocop.yml b/.rubocop.yml
index 2e7c69e..d420c8d 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,3 +1,11 @@
+# This configuration was generated by
+# `rubocop --auto-gen-config`
+# on 2016-04-18 08:55:15 -0700 using RuboCop version 0.33.0.
+# The point is for the user to remove these configuration records
+# one by one as the offenses are removed from the code base.
+# Note that changes in the inspected code, or installation of new
+# versions of RuboCop, may require this file to be generated again.
+
 LineLength:
   Max: 200
 
@@ -7,6 +15,30 @@ Documentation:
 StringLiterals:
   EnforcedStyle: single_quotes
 
+# Offense count: 7
+Metrics/AbcSize:
+  Max: 25
+
+# Offense count: 2
+Metrics/CyclomaticComplexity:
+  Max: 7
+
+# Offense count: 5
+# Configuration parameters: CountComments.
+Metrics/MethodLength:
+  Max: 19
+
+# Offense count: 1
+# Configuration parameters: CountComments.
+Metrics/ModuleLength:
+  Max: 123
+
+# Offense count: 3
+Style/RescueModifier:
+  Exclude:
+    - 'lib/gitx/cli/integrate_command.rb'
+    - 'lib/gitx/cli/nuke_command.rb'
+
 FileName:
   Exclude:
     - bin/*
diff --git a/Rakefile b/Rakefile
index ede4b71..8a2f2ca 100644
--- a/Rakefile
+++ b/Rakefile
@@ -3,3 +3,7 @@ require 'bundler/gem_tasks'
 require 'rspec/core/rake_task'
 RSpec::Core::RakeTask.new('spec')
 task default: :spec
+
+require 'rubocop/rake_task'
+RuboCop::RakeTask.new
+task default: :rubocop
diff --git a/lib/gitx/cli/base_command.rb b/lib/gitx/cli/base_command.rb
index 761a48e..b8f8b67 100644
--- a/lib/gitx/cli/base_command.rb
+++ b/lib/gitx/cli/base_command.rb
@@ -42,11 +42,11 @@ def current_branch
       end
 
       def assert_aggregate_branch!(target_branch)
-        fail "Invalid aggregate branch: #{target_branch} must be one of supported aggregate branches #{config.aggregate_branches}" unless config.aggregate_branch?(target_branch)
+        raise "Invalid aggregate branch: #{target_branch} must be one of supported aggregate branches #{config.aggregate_branches}" unless config.aggregate_branch?(target_branch)
       end
 
       def assert_not_protected_branch!(branch, action)
-        fail "Cannot #{action} reserved branch" if config.reserved_branch?(branch) || config.aggregate_branch?(branch)
+        raise "Cannot #{action} reserved branch" if config.reserved_branch?(branch) || config.aggregate_branch?(branch)
       end
 
       def config
diff --git a/lib/gitx/cli/buildtag_command.rb b/lib/gitx/cli/buildtag_command.rb
index 7cfcd61..410fecf 100644
--- a/lib/gitx/cli/buildtag_command.rb
+++ b/lib/gitx/cli/buildtag_command.rb
@@ -9,7 +9,7 @@ class BuildtagCommand < BaseCommand
       method_option :branch, type: :string, aliases: '-b', desc: 'branch name for build tag'
       method_option :message, type: :string, aliases: '-m', desc: 'message to attach to the buildtag'
       def buildtag
-        fail "Branch must be one of the supported taggable branches: #{config.taggable_branches}" unless config.taggable_branch?(branch_name)
+        raise "Branch must be one of the supported taggable branches: #{config.taggable_branches}" unless config.taggable_branch?(branch_name)
         run_git_cmd 'tag', git_tag, '--annotate', '--message', label
         run_git_cmd 'push', 'origin', git_tag
       end
diff --git a/lib/gitx/cli/cleanup_command.rb b/lib/gitx/cli/cleanup_command.rb
index 47222de..3910362 100644
--- a/lib/gitx/cli/cleanup_command.rb
+++ b/lib/gitx/cli/cleanup_command.rb
@@ -7,38 +7,47 @@ module Cli
     class CleanupCommand < BaseCommand
       desc 'cleanup', 'Cleanup branches that have been merged into master from the repo'
       def cleanup
-        checkout_branch config.base_branch
-        run_git_cmd 'pull'
-        run_git_cmd 'remote', 'prune', 'origin'
-
+        update_base_branch
         say 'Deleting local and remote branches that have been merged into '
         say config.base_branch, :green
-        merged_branches(remote: true).each do |branch|
+        filtered_merged_branches(:remote).each do |branch|
           run_git_cmd 'push', 'origin', '--delete', branch
         end
-        merged_branches(remote: false).each do |branch|
+        filtered_merged_branches(:local).each do |branch|
           run_git_cmd 'branch', '--delete', branch
         end
       end
 
       private
 
+      def update_base_branch
+        checkout_branch config.base_branch
+        run_git_cmd 'pull'
+        run_git_cmd 'remote', 'prune', 'origin'
+      end
+
       # @return list of branches that have been merged
-      def merged_branches(options = {})
-        args = []
-        args << '--remote' if options[:remote]
-        args << '--merged'
-        output = run_git_cmd('branch', *args).split("\n")
-        branches = output.map do |branch|
-          branch = branch.gsub(/\*/, '').strip.split(' ').first
-          branch = branch.gsub('origin/', '') if options[:remote]
-          branch
+      # filter out reserved and aggregate branches
+      def filtered_merged_branches(source)
+        merged_branches(source).reject do |branch|
+          config.reserved_branches.include?(branch) || config.aggregate_branch?(branch)
         end
-        branches.uniq!
-        branches -= config.reserved_branches
-        branches.reject! { |b| config.aggregate_branch?(b) }
+      end
+
+      # @return list of branches that have been merged
+      # see http://stackoverflow.com/questions/26804024/git-branch-merged-sha-via-rugged-libgit2-bindings
+      def merged_branches(source)
+        merged_branches = repo.branches.each(source).select do |branch|
+          target = branch.resolve.target
+          repo.merge_base(base_branch_merge_target, target) == target.oid
+        end
+        merged_branches.map do |branch|
+          branch.name.gsub('origin/', '')
+        end
+      end
 
-        branches
+      def base_branch_merge_target
+        repo.head.target
       end
     end
   end
diff --git a/lib/gitx/cli/nuke_command.rb b/lib/gitx/cli/nuke_command.rb
index 2375e05..9331496 100644
--- a/lib/gitx/cli/nuke_command.rb
+++ b/lib/gitx/cli/nuke_command.rb
@@ -9,7 +9,7 @@ class NukeCommand < BaseCommand
       method_option :destination, type: :string, aliases: '-d', desc: 'destination branch to reset to'
       def nuke(bad_branch)
         good_branch = options[:destination] || ask("What branch do you want to reset #{bad_branch} to? (default: #{bad_branch})")
-        good_branch = bad_branch if good_branch.length == 0
+        good_branch = bad_branch if good_branch.empty?
 
         last_known_good_tag = current_build_tag(good_branch)
         return unless yes?("Reset #{bad_branch} to #{last_known_good_tag}? (y/n)", :green)
@@ -47,7 +47,7 @@ def migrations_need_to_be_reverted?(bad_branch, last_known_good_tag)
 
       def current_build_tag(branch)
         last_build_tag = build_tags_for_branch(branch).last
-        fail "No known good tag found for branch: #{branch}.  Verify tag exists via `git tag -l 'build-#{branch}-*'`" unless last_build_tag
+        raise "No known good tag found for branch: #{branch}.  Verify tag exists via `git tag -l 'build-#{branch}-*'`" unless last_build_tag
         last_build_tag
       end
 
diff --git a/lib/gitx/cli/review_command.rb b/lib/gitx/cli/review_command.rb
index f738130..53724ba 100644
--- a/lib/gitx/cli/review_command.rb
+++ b/lib/gitx/cli/review_command.rb
@@ -8,14 +8,14 @@ module Cli
     class ReviewCommand < BaseCommand
       include Gitx::Github
 
-      BUMP_COMMENT_PREFIX = '[gitx] review bump :tada:'
+      BUMP_COMMENT_PREFIX = '[gitx] review bump :tada:'.freeze
       BUMP_COMMENT_FOOTER = <<-EOS.dedent
         # Bump comments should include:
         # * Summary of what changed
         #
         # This footer will automatically be stripped from the created comment
       EOS
-      APPROVAL_COMMENT_PREFIX  = '[gitx] review approved :shipit:'
+      APPROVAL_COMMENT_PREFIX = '[gitx] review approved :shipit:'.freeze
       APPROVAL_COMMENT_FOOTER = <<-EOS.dedent
         # Approval comments can include:
         # * Feedback
@@ -23,7 +23,7 @@ class ReviewCommand < BaseCommand
         #
         # This footer will automatically be stripped from the created comment
       EOS
-      REJECTION_COMMENT_PREFIX = '[gitx] review rejected'
+      REJECTION_COMMENT_PREFIX = '[gitx] review rejected'.freeze
       REJECTION_COMMENT_FOOTER = <<-EOS.dedent
         # Rejection comments should include:
         # * Feedback
@@ -42,7 +42,7 @@ class ReviewCommand < BaseCommand
       method_option :reject, type: :boolean, desc: 'reject the pull request an post comment on pull request'
       # @see http://developer.github.com/v3/pulls/
       def review(branch = nil)
-        fail 'Github authorization token not found' unless authorization_token
+        raise 'Github authorization token not found' unless authorization_token
 
         branch ||= current_branch.name
         pull_request = find_or_create_pull_request(branch)
diff --git a/lib/gitx/cli/start_command.rb b/lib/gitx/cli/start_command.rb
index 0766ecf..bec0bfa 100644
--- a/lib/gitx/cli/start_command.rb
+++ b/lib/gitx/cli/start_command.rb
@@ -5,7 +5,7 @@
 module Gitx
   module Cli
     class StartCommand < BaseCommand
-      EXAMPLE_BRANCH_NAMES = %w( api-fix-invalid-auth desktop-cleanup-avatar-markup share-form-add-edit-link )
+      EXAMPLE_BRANCH_NAMES = %w( api-fix-invalid-auth desktop-cleanup-avatar-markup share-form-add-edit-link ).freeze
       VALID_BRANCH_NAME_REGEX = /^[A-Za-z0-9\-_]+$/
 
       desc 'start', 'start a new git branch with latest changes from master'
diff --git a/lib/gitx/configuration.rb b/lib/gitx/configuration.rb
index 9cf6bd6..a190705 100644
--- a/lib/gitx/configuration.rb
+++ b/lib/gitx/configuration.rb
@@ -3,7 +3,7 @@
 
 module Gitx
   class Configuration
-    CONFIG_FILE = '.gitx.yml'
+    CONFIG_FILE = '.gitx.yml'.freeze
 
     attr_reader :config
 
diff --git a/lib/gitx/executor.rb b/lib/gitx/executor.rb
index 1f0049e..e8429b6 100644
--- a/lib/gitx/executor.rb
+++ b/lib/gitx/executor.rb
@@ -11,14 +11,16 @@ def execute(*cmd)
       yield "$ #{cmd.join(' ')}" if block_given?
       output = ''
 
-      Open3.popen2e(*cmd) do |stdin, stdout_err, wait_thread|
-        while line = stdout_err.gets
+      Open3.popen2e(*cmd) do |_stdin, stdout_err, wait_thread|
+        loop do
+          line = stdout_err.gets
+          break unless line
           output << line
           yield line if block_given?
         end
 
         exit_status = wait_thread.value
-        fail ExecutionError, "#{cmd.join(' ')} failed" unless exit_status.success?
+        raise ExecutionError, "#{cmd.join(' ')} failed" unless exit_status.success?
       end
       output
     end
diff --git a/lib/gitx/extensions/string.rb b/lib/gitx/extensions/string.rb
index 5a41d02..b32078d 100644
--- a/lib/gitx/extensions/string.rb
+++ b/lib/gitx/extensions/string.rb
@@ -4,7 +4,7 @@ def undent
     indent = scan(/^[ \t]*(?=\S)/).min.size || 0
     gsub(/^[ \t]{#{indent}}/, '')
   end
-  alias_method :dedent, :undent
+  alias dedent undent
 
   def blank?
     to_s == ''
diff --git a/lib/gitx/extensions/thor.rb b/lib/gitx/extensions/thor.rb
index b48ea00..56fdcc7 100644
--- a/lib/gitx/extensions/thor.rb
+++ b/lib/gitx/extensions/thor.rb
@@ -12,13 +12,13 @@ def ask_editor(initial_text = '', editor: nil, footer: nil)
         f.flush
 
         flags = case editor
-        when 'mate', 'emacs', 'subl'
-          '-w'
-        when 'mvim'
-          '-f'
-        else
-          ''
-        end
+                when 'mate', 'emacs', 'subl'
+                  '-w'
+                when 'mvim'
+                  '-f'
+                else
+                  ''
+                end
         pid = fork { exec([editor, flags, f.path].join(' ')) }
         Process.waitpid(pid)
         File.read(f.path)
diff --git a/lib/gitx/github.rb b/lib/gitx/github.rb
index 152f491..0437e54 100644
--- a/lib/gitx/github.rb
+++ b/lib/gitx/github.rb
@@ -4,9 +4,9 @@
 
 module Gitx
   module Github
-    GLOBAL_CONFIG_FILE = '~/.config/gitx/github.yml'
-    REVIEW_CONTEXT = 'peer_review'
-    CLIENT_URL = 'https://github.com/wireframe/gitx'
+    GLOBAL_CONFIG_FILE = '~/.config/gitx/github.yml'.freeze
+    REVIEW_CONTEXT = 'peer_review'.freeze
+    CLIENT_URL = 'https://github.com/wireframe/gitx'.freeze
     PULL_REQUEST_FOOTER = <<-EOS.dedent
       # Pull Request Protips(tm):
       # * Describe how this change accomplishes the task at hand
@@ -72,14 +72,14 @@ def create_pull_request(branch)
     end
 
     def pull_request_body(branch)
-      changelog = run_git_cmd('log', "origin/#{config.base_branch}...#{branch}", '--reverse', '--no-merges', "--pretty=format:* %B")
+      changelog = run_git_cmd('log', "origin/#{config.base_branch}...#{branch}", '--reverse', '--no-merges', '--pretty=format:* %B')
       description = options[:description]
 
       description_template = []
       description_template << "#{description}\n" if description
       description_template << changelog
 
-      body = ask_editor(description_template.join("\n"), editor: repo.config['core.editor'], footer: PULL_REQUEST_FOOTER)
+      ask_editor(description_template.join("\n"), editor: repo.config['core.editor'], footer: PULL_REQUEST_FOOTER)
     end
 
     def pull_request_title(branch)
@@ -120,7 +120,7 @@ def create_authorization
 
     def github_client_name
       timestamp = Time.now.utc.strftime('%FT%R:%S%z')
-      client_name = "Git eXtensions #{timestamp}"
+      "Git eXtensions #{timestamp}"
     end
 
     def github_client
@@ -131,7 +131,7 @@ def github_client
     # @raise error if github.user is not configured
     def username
       username = repo.config['github.user']
-      fail "Github user not configured.  Run: `git config --global github.user 'me@email.com'`" unless username
+      raise "Github user not configured.  Run: `git config --global github.user 'me@email.com'`" unless username
       username
     end
 
@@ -142,7 +142,7 @@ def username
     #   https://github.com/wireframe/gitx.git #=> wireframe/gitx
     def github_slug
       remote = repo.config['remote.origin.url']
-      remote.to_s.gsub(/\.git$/, '').split(/[:\/]/).last(2).join('/')
+      remote.to_s.gsub(/\.git$/, '').split(%r{[:\/]}).last(2).join('/')
     end
 
     def github_organization
diff --git a/lib/gitx/version.rb b/lib/gitx/version.rb
index 6fb5da4..d00c4a8 100644
--- a/lib/gitx/version.rb
+++ b/lib/gitx/version.rb
@@ -1,3 +1,3 @@
 module Gitx
-  VERSION = '2.23.0'
+  VERSION = '2.23.1'.freeze
 end
diff --git a/spec/gitx/cli/cleanup_command_spec.rb b/spec/gitx/cli/cleanup_command_spec.rb
index ad217e8..8279983 100644
--- a/spec/gitx/cli/cleanup_command_spec.rb
+++ b/spec/gitx/cli/cleanup_command_spec.rb
@@ -11,20 +11,29 @@
   end
   let(:cli) { described_class.new(args, options, config) }
   let(:executor) { cli.send(:executor) }
-  let(:branch) { double('fake branch', name: 'feature-branch') }
-  let(:remote_branches) { '' }
-  let(:local_branches) { '' }
+  let(:remote_branches) { [] }
+  let(:local_branches) { [] }
+  let(:workdir) { '.' }
+  let(:oid) { '123123' }
+  let(:target) { double(:target, oid: oid) }
+  let(:reference) { double(:ref, target: target) }
+  let(:repo) { double(:repo, workdir: workdir, head: reference) }
+  let(:branches) { double(:branches) }
 
   before do
-    allow(cli).to receive(:current_branch).and_return(branch)
+    allow(cli).to receive(:repo).and_return(repo)
+    allow(repo).to receive(:branches).and_return(branches)
+    allow(repo).to receive(:merge_base).with(target, target).and_return(oid)
+    allow(branches).to receive(:each).with(:local).and_return(local_branches)
+    allow(branches).to receive(:each).with(:remote).and_return(remote_branches)
   end
 
   describe '#cleanup' do
     context 'when merged local branches exist' do
       let(:local_branches) do
-        <<-EOS.dedent
-        merged-local-feature
-        EOS
+        [
+          double(:branch, name: 'merged-local-feature', resolve: reference)
+        ]
       end
       before do
         allow(cli).to receive(:say)
@@ -32,8 +41,6 @@
         expect(executor).to receive(:execute).with('git', 'checkout', 'master').ordered
         expect(executor).to receive(:execute).with('git', 'pull').ordered
         expect(executor).to receive(:execute).with('git', 'remote', 'prune', 'origin').ordered
-        expect(executor).to receive(:execute).with('git', 'branch', '--remote', '--merged').and_return(remote_branches).ordered
-        expect(executor).to receive(:execute).with('git', 'branch', '--merged').and_return(local_branches).ordered
         expect(executor).to receive(:execute).with('git', 'branch', '--delete', 'merged-local-feature').ordered
 
         cli.cleanup
@@ -44,9 +51,9 @@
     end
     context 'when merged remote branches exist' do
       let(:remote_branches) do
-        <<-EOS.dedent
-        origin/merged-remote-feature
-        EOS
+        [
+          double(:branch, name: 'origin/merged-remote-feature', resolve: reference)
+        ]
       end
       before do
         allow(cli).to receive(:say)
@@ -54,9 +61,7 @@
         expect(executor).to receive(:execute).with('git', 'checkout', 'master').ordered
         expect(executor).to receive(:execute).with('git', 'pull').ordered
         expect(executor).to receive(:execute).with('git', 'remote', 'prune', 'origin').ordered
-        expect(executor).to receive(:execute).with('git', 'branch', '--remote', '--merged').and_return(remote_branches).ordered
         expect(executor).to receive(:execute).with('git', 'push', 'origin', '--delete', 'merged-remote-feature').ordered
-        expect(executor).to receive(:execute).with('git', 'branch', '--merged').and_return(local_branches).ordered
 
         cli.cleanup
       end
@@ -66,9 +71,9 @@
     end
     context 'when mreged remote branches with slash exist' do
       let(:remote_branches) do
-        <<-EOS.dedent
-        origin/merged-remote-feature/review
-        EOS
+        [
+          double(:branch, name: 'origin/merged-remote-feature/review', resolve: reference)
+        ]
       end
       before do
         allow(cli).to receive(:say)
@@ -76,9 +81,7 @@
         expect(executor).to receive(:execute).with('git', 'checkout', 'master').ordered
         expect(executor).to receive(:execute).with('git', 'pull').ordered
         expect(executor).to receive(:execute).with('git', 'remote', 'prune', 'origin').ordered
-        expect(executor).to receive(:execute).with('git', 'branch', '--remote', '--merged').and_return(remote_branches).ordered
         expect(executor).to receive(:execute).with('git', 'push', 'origin', '--delete', 'merged-remote-feature/review').ordered
-        expect(executor).to receive(:execute).with('git', 'branch', '--merged').and_return(local_branches).ordered
 
         cli.cleanup
       end
diff --git a/spec/gitx/cli/integrate_command_spec.rb b/spec/gitx/cli/integrate_command_spec.rb
index ab50a5c..cf72bbe 100644
--- a/spec/gitx/cli/integrate_command_spec.rb
+++ b/spec/gitx/cli/integrate_command_spec.rb
@@ -84,7 +84,7 @@
         expect(executor).to receive(:execute).with('git', 'update').ordered
         expect(executor).to receive(:execute).with('git', 'checkout', 'feature-branch').ordered
         expect(executor).to receive(:execute).with('git', 'update').ordered
-        expect(executor).to receive(:execute).with('git', 'log', 'origin/master...feature-branch', '--reverse', '--no-merges', "--pretty=format:* %B").and_return(changelog).ordered
+        expect(executor).to receive(:execute).with('git', 'log', 'origin/master...feature-branch', '--reverse', '--no-merges', '--pretty=format:* %B').and_return(changelog).ordered
         expect(executor).to receive(:execute).with('git', 'fetch', 'origin').ordered
         expect(executor).to receive(:execute).with('git', 'branch', '--delete', '--force', 'staging').ordered
         expect(executor).to receive(:execute).with('git', 'checkout', 'staging').ordered
@@ -158,7 +158,8 @@
         expect(executor).to receive(:execute).with('git', 'fetch', 'origin').ordered
         expect(executor).to receive(:execute).with('git', 'branch', '--delete', '--force', 'staging').ordered
         expect(executor).to receive(:execute).with('git', 'checkout', 'staging').ordered
-        expect(executor).to receive(:execute).with('git', 'merge', '--no-ff', '--message', '[gitx] Integrating feature-branch into staging (Pull request #10)', 'feature-branch').and_raise('git merge feature-branch failed').ordered
+        expect(executor).to receive(:execute).with('git', 'merge', '--no-ff', '--message', '[gitx] Integrating feature-branch into staging (Pull request #10)', 'feature-branch')
+          .and_raise('git merge feature-branch failed').ordered
 
         VCR.use_cassette('pull_request_does_exist_with_success_status') do
           expect { cli.integrate }.to raise_error(/Merge conflict occurred.  Please fix merge conflict and rerun command with --resume feature-branch flag/)
diff --git a/spec/gitx/cli/release_command_spec.rb b/spec/gitx/cli/release_command_spec.rb
index 01427b3..5ac94f7 100644
--- a/spec/gitx/cli/release_command_spec.rb
+++ b/spec/gitx/cli/release_command_spec.rb
@@ -152,7 +152,7 @@
         expect(executor).to receive(:execute).with('git', 'update').ordered
         expect(executor).to receive(:execute).with('git', 'checkout', 'feature-branch').ordered
         expect(executor).to receive(:execute).with('git', 'update').ordered
-        expect(executor).to receive(:execute).with('git', 'log', 'origin/master...feature-branch', '--reverse', '--no-merges', "--pretty=format:* %B").and_return('2013-01-01 did some stuff').ordered
+        expect(executor).to receive(:execute).with('git', 'log', 'origin/master...feature-branch', '--reverse', '--no-merges', '--pretty=format:* %B').and_return('2013-01-01 did some stuff').ordered
         expect(executor).to receive(:execute).with('git', 'checkout', 'master').ordered
         expect(executor).to receive(:execute).with('git', 'pull', 'origin', 'master').ordered
         expect(executor).to receive(:execute).with('git', 'merge', '--no-ff', '--message', '[gitx] Releasing feature-branch to master (Pull request #10)', 'feature-branch').ordered
diff --git a/spec/gitx/cli/review_command_spec.rb b/spec/gitx/cli/review_command_spec.rb
index b3e2aa9..05e36d3 100644
--- a/spec/gitx/cli/review_command_spec.rb
+++ b/spec/gitx/cli/review_command_spec.rb
@@ -46,7 +46,7 @@
         allow(cli).to receive(:authorization_token).and_return(authorization_token)
         expect(executor).to receive(:execute).with('git', 'checkout', 'feature-branch').ordered
         expect(executor).to receive(:execute).with('git', 'update').ordered
-        expect(executor).to receive(:execute).with('git', 'log', 'origin/master...feature-branch', '--reverse', '--no-merges', "--pretty=format:* %B").and_return(changelog).ordered
+        expect(executor).to receive(:execute).with('git', 'log', 'origin/master...feature-branch', '--reverse', '--no-merges', '--pretty=format:* %B').and_return(changelog).ordered
         expect(cli).to receive(:ask_editor).with(changelog, hash_including(footer: Gitx::Github::PULL_REQUEST_FOOTER)).and_return('description')
 
         stub_request(:post, 'https://api.github.com/repos/wireframe/gitx/pulls').to_return(status: 201, body: new_pull_request.to_json, headers: { 'Content-Type' => 'application/json' })
@@ -82,11 +82,11 @@
         allow(cli).to receive(:authorization_token).and_return(authorization_token)
         expect(executor).to receive(:execute).with('git', 'checkout', 'feature-branch').ordered
         expect(executor).to receive(:execute).with('git', 'update').ordered
-        expect(executor).to receive(:execute).with('git', 'log', 'origin/master...feature-branch', '--reverse', '--no-merges', "--pretty=format:* %B").and_return(changelog).ordered
+        expect(executor).to receive(:execute).with('git', 'log', 'origin/master...feature-branch', '--reverse', '--no-merges', '--pretty=format:* %B').and_return(changelog).ordered
         expect(cli).to receive(:ask_editor).with(changelog, hash_including(footer: Gitx::Github::PULL_REQUEST_FOOTER)).and_return(pull_request_description)
 
         stub_request(:post, 'https://api.github.com/repos/wireframe/gitx/pulls')
-          .with(body: {base: 'master', head: 'feature-branch', title: 'feature branch', body: pull_request_description}.to_json)
+          .with(body: { base: 'master', head: 'feature-branch', title: 'feature branch', body: pull_request_description }.to_json)
           .to_return(status: 201, body: new_pull_request.to_json, headers: { 'Content-Type' => 'application/json' })
 
         VCR.use_cassette('pull_request_does_not_exist') do
diff --git a/spec/support/stub_execution.rb b/spec/support/stub_execution.rb
index 88e705a..cfa5743 100644
--- a/spec/support/stub_execution.rb
+++ b/spec/support/stub_execution.rb
@@ -9,6 +9,6 @@ def execute_with_stub(cmd)
     end
   end
 
-  alias_method :execute_without_stub, :`
-  alias_method :`, :execute_with_stub
+  alias execute_without_stub `
+  alias ` execute_with_stub
 end