diff --git a/Vagrantfile b/Vagrantfile
index d26bf7c..cd22054 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -1,24 +1,24 @@
+# frozen_string_literal: true
+
 # -*- mode: ruby -*-
 # vi: set ft=ruby :
 
 # Vagrantfile API/syntax version. Don't touch unless you know what you're doing!
-VAGRANTFILE_API_VERSION = "2"
+VAGRANTFILE_API_VERSION = '2'
 
 Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
-  config.vm.box = "ubuntu/trusty64"
-  config.vm.hostname = "salt"
-  config.vm.synced_folder "./", "/srv/salt", id: "vagrant-root"
+  config.vm.box = 'ubuntu/trusty64'
+  config.vm.hostname = 'salt'
+  config.vm.synced_folder './', '/srv/salt', id: 'vagrant-root'
 
   config.ssh.forward_agent = true
 
   config.vm.provider :virtualbox do |vb|
     # Use VBoxManage to customize the VM. For example to change memory:
-    vb.customize ["modifyvm", :id, "--memory", "1024"]
-  end
-  if Vagrant.has_plugin?("vagrant-cachier")
-    config.cache.scope = :box
+    vb.customize ['modifyvm', :id, '--memory', '1024']
   end
+  config.cache.scope = :box if Vagrant.has_plugin?('vagrant-cachier')
 
   # Set up salt-master and minion
-  config.vm.provision "shell", path: "dev/setup-salt.sh"
+  config.vm.provision 'shell', path: 'dev/setup-salt.sh'
 end
diff --git a/test/integration/v201707-py2/controls/pkgs_spec.rb b/test/integration/v201707-py2/controls/pkgs_spec.rb
index 5ef8347..2d09b69 100644
--- a/test/integration/v201707-py2/controls/pkgs_spec.rb
+++ b/test/integration/v201707-py2/controls/pkgs_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 version =
   case platform[:family]
   when 'redhat'
@@ -14,10 +16,10 @@ version =
 control 'salt packages' do
   title 'should be installed'
 
-  %w(
+  %w[
     salt-master
     salt-minion
-  ).each do |p|
+  ].each do |p|
     describe package(p) do
       it { should be_installed }
       its('version') { should eq version }
diff --git a/test/integration/v201707-py2/controls/service_spec.rb b/test/integration/v201707-py2/controls/service_spec.rb
index d0255e6..27f8ae5 100644
--- a/test/integration/v201707-py2/controls/service_spec.rb
+++ b/test/integration/v201707-py2/controls/service_spec.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 control 'salt services' do
   title 'should be running'
 
-  %w(
+  %w[
     salt-master
     salt-minion
-  ).each do |p|
+  ].each do |p|
     describe service(p) do
       it { should be_enabled }
       it { should be_running }
diff --git a/test/integration/v201803-py2/controls/pkgs_spec.rb b/test/integration/v201803-py2/controls/pkgs_spec.rb
index 37f5aae..f9e748b 100644
--- a/test/integration/v201803-py2/controls/pkgs_spec.rb
+++ b/test/integration/v201803-py2/controls/pkgs_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 version =
   case platform[:family]
   when 'redhat'
@@ -9,10 +11,10 @@ version =
 control 'salt packages' do
   title 'should be installed'
 
-  %w(
+  %w[
     salt-master
     salt-minion
-  ).each do |p|
+  ].each do |p|
     describe package(p) do
       it { should be_installed }
       its('version') { should eq version }
diff --git a/test/integration/v201803-py2/controls/service_spec.rb b/test/integration/v201803-py2/controls/service_spec.rb
index d0255e6..27f8ae5 100644
--- a/test/integration/v201803-py2/controls/service_spec.rb
+++ b/test/integration/v201803-py2/controls/service_spec.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 control 'salt services' do
   title 'should be running'
 
-  %w(
+  %w[
     salt-master
     salt-minion
-  ).each do |p|
+  ].each do |p|
     describe service(p) do
       it { should be_enabled }
       it { should be_running }
diff --git a/test/integration/v201902-py2/controls/pkgs_spec.rb b/test/integration/v201902-py2/controls/pkgs_spec.rb
index a5ed397..eceafb0 100644
--- a/test/integration/v201902-py2/controls/pkgs_spec.rb
+++ b/test/integration/v201902-py2/controls/pkgs_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 version =
   case platform[:family]
   when 'redhat'
@@ -13,10 +15,10 @@ version =
 control 'salt packages' do
   title 'should be installed'
 
-  %w(
+  %w[
     salt-master
     salt-minion
-  ).each do |p|
+  ].each do |p|
     describe package(p) do
       it { should be_installed }
       its('version') { should eq version }
diff --git a/test/integration/v201902-py2/controls/service_spec.rb b/test/integration/v201902-py2/controls/service_spec.rb
index d0255e6..27f8ae5 100644
--- a/test/integration/v201902-py2/controls/service_spec.rb
+++ b/test/integration/v201902-py2/controls/service_spec.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 control 'salt services' do
   title 'should be running'
 
-  %w(
+  %w[
     salt-master
     salt-minion
-  ).each do |p|
+  ].each do |p|
     describe service(p) do
       it { should be_enabled }
       it { should be_running }
diff --git a/test/integration/v201902-py3/controls/pkgs_spec.rb b/test/integration/v201902-py3/controls/pkgs_spec.rb
index 99b1b27..a840026 100644
--- a/test/integration/v201902-py3/controls/pkgs_spec.rb
+++ b/test/integration/v201902-py3/controls/pkgs_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 version =
   case platform[:family]
   when 'redhat'
@@ -18,10 +20,10 @@ version =
 control 'salt packages' do
   title 'should be installed'
 
-  %w(
+  %w[
     salt-master
     salt-minion
-  ).each do |p|
+  ].each do |p|
     describe package(p) do
       it { should be_installed }
       its('version') { should eq version }
diff --git a/test/integration/v201902-py3/controls/service_spec.rb b/test/integration/v201902-py3/controls/service_spec.rb
index d0255e6..27f8ae5 100644
--- a/test/integration/v201902-py3/controls/service_spec.rb
+++ b/test/integration/v201902-py3/controls/service_spec.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 control 'salt services' do
   title 'should be running'
 
-  %w(
+  %w[
     salt-master
     salt-minion
-  ).each do |p|
+  ].each do |p|
     describe service(p) do
       it { should be_enabled }
       it { should be_running }