diff --git a/.rubocop.yml b/.rubocop.yml
index 3783e6b75..14c89afd4 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -72,11 +72,6 @@ Style/StringLiterals:
 Style/SymbolArray:
   EnforcedStyle: brackets
 
-# Code is currently broken with frozen string literal comments applied.
-# TODO: Enable and fix build
-Style/FrozenStringLiteralComment:
-  Enabled: false
-
 # Be relatively lenient with line length
 Layout/LineLength:
   Max: 94
diff --git a/.simplecov b/.simplecov
index d4f5685b6..6fe22f24d 100644
--- a/.simplecov
+++ b/.simplecov
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 SimpleCov.configure do
   # Activate branch coverage
   enable_coverage :branch
diff --git a/Gemfile b/Gemfile
index 3c7cea132..505ac864d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
 # Use dependencies from gemspec
diff --git a/Rakefile b/Rakefile
index 81d742e99..848ca81f4 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH << File.expand_path(__dir__)
 
 require "aruba/platform"
diff --git a/aruba.gemspec b/aruba.gemspec
index 12faf7853..57a08587a 100644
--- a/aruba.gemspec
+++ b/aruba.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "lib/aruba/version"
 
 Gem::Specification.new do |spec|
diff --git a/bin/console b/bin/console
index 1b23406c1..11f3ee2ee 100755
--- a/bin/console
+++ b/bin/console
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 $LOAD_PATH.unshift File.expand_path("../lib", __dir__)
 
diff --git a/exe/aruba b/exe/aruba
index 6adbd500c..9e3365d21 100755
--- a/exe/aruba
+++ b/exe/aruba
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 $LOAD_PATH << File.expand_path("../lib", __dir__)
 
diff --git a/features/step_definitions/hooks.rb b/features/step_definitions/hooks.rb
index 1facf2c7a..e65a52c59 100644
--- a/features/step_definitions/hooks.rb
+++ b/features/step_definitions/hooks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cucumber/platform"
 
 Before "@requires-python" do
diff --git a/features/support/aruba.rb b/features/support/aruba.rb
index cde25f461..1533e51ad 100644
--- a/features/support/aruba.rb
+++ b/features/support/aruba.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/cucumber"
 
 Aruba.configure do |config|
diff --git a/features/support/env.rb b/features/support/env.rb
index 4a4e7fb06..27efd8bfe 100644
--- a/features/support/env.rb
+++ b/features/support/env.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH.unshift File.expand_path("../../lib", __dir__)
 
 # Has to be the first file required so that all other files show coverage information
diff --git a/features/support/jruby.rb b/features/support/jruby.rb
index 61de3c582..47bede405 100644
--- a/features/support/jruby.rb
+++ b/features/support/jruby.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 if RUBY_PLATFORM == "java"
   Before do
     @aruba_timeout_seconds = 15
diff --git a/features/support/simplecov_setup.rb b/features/support/simplecov_setup.rb
index 598dc8673..41d96ce74 100644
--- a/features/support/simplecov_setup.rb
+++ b/features/support/simplecov_setup.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @note this file is loaded in env.rb to setup simplecov using RUBYOPTs for
 # child processes and @in-process
 unless RUBY_PLATFORM.include?("java")
diff --git a/features/support/timing.rb b/features/support/timing.rb
index 23b4e3331..4ff1470ef 100644
--- a/features/support/timing.rb
+++ b/features/support/timing.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # From https://itshouldbeuseful.wordpress.com/2010/11/10/find-your-slowest-running-cucumber-features/
 
 scenario_times = {}
diff --git a/fixtures/cli-app/Gemfile b/fixtures/cli-app/Gemfile
index ef0ed48d5..1a48fccdf 100644
--- a/fixtures/cli-app/Gemfile
+++ b/fixtures/cli-app/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
 # Use dependencies from gemspec
diff --git a/fixtures/cli-app/Rakefile b/fixtures/cli-app/Rakefile
index 29955274e..5263b5839 100644
--- a/fixtures/cli-app/Rakefile
+++ b/fixtures/cli-app/Rakefile
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 require "bundler/gem_tasks"
diff --git a/fixtures/cli-app/bin/aruba-test-cli b/fixtures/cli-app/bin/aruba-test-cli
index 70e0f203e..c4ab1d75d 100755
--- a/fixtures/cli-app/bin/aruba-test-cli
+++ b/fixtures/cli-app/bin/aruba-test-cli
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 $LOAD_PATH << File.expand_path("../lib", __dir__)
 require "cli/app"
diff --git a/fixtures/cli-app/cli-app.gemspec b/fixtures/cli-app/cli-app.gemspec
index 37f1e5376..f4b99a262 100644
--- a/fixtures/cli-app/cli-app.gemspec
+++ b/fixtures/cli-app/cli-app.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 lib = File.expand_path("lib", __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require "cli/app/version"
diff --git a/fixtures/cli-app/features/support/aruba.rb b/fixtures/cli-app/features/support/aruba.rb
index ba5a3303d..25a3b5d1d 100644
--- a/fixtures/cli-app/features/support/aruba.rb
+++ b/fixtures/cli-app/features/support/aruba.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 require "aruba/cucumber"
diff --git a/fixtures/cli-app/features/support/env.rb b/fixtures/cli-app/features/support/env.rb
index 217b8f5eb..deebd5269 100644
--- a/fixtures/cli-app/features/support/env.rb
+++ b/fixtures/cli-app/features/support/env.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 require_relative "aruba"
diff --git a/fixtures/cli-app/lib/cli/app.rb b/fixtures/cli-app/lib/cli/app.rb
index 3efb22b8f..532ae4c72 100644
--- a/fixtures/cli-app/lib/cli/app.rb
+++ b/fixtures/cli-app/lib/cli/app.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cli/app/version"
 
 Dir.glob(File.expand_path("**/*.rb", __dir__)).each { |f| require_relative f }
diff --git a/fixtures/cli-app/lib/cli/app/suppress_simple_cov_output.rb b/fixtures/cli-app/lib/cli/app/suppress_simple_cov_output.rb
index dce7c16c8..506aa449c 100644
--- a/fixtures/cli-app/lib/cli/app/suppress_simple_cov_output.rb
+++ b/fixtures/cli-app/lib/cli/app/suppress_simple_cov_output.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module SimpleCov
   module Formatter
     class HTMLFormatter
diff --git a/fixtures/cli-app/lib/cli/app/version.rb b/fixtures/cli-app/lib/cli/app/version.rb
index f2f5d822d..69e6983ae 100644
--- a/fixtures/cli-app/lib/cli/app/version.rb
+++ b/fixtures/cli-app/lib/cli/app/version.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 module Cli
   module App
-    VERSION = "0.1.0".freeze
+    VERSION = "0.1.0"
   end
 end
diff --git a/fixtures/cli-app/script/console b/fixtures/cli-app/script/console
index 1a4888ae7..b7f138e67 100755
--- a/fixtures/cli-app/script/console
+++ b/fixtures/cli-app/script/console
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 require "bundler/setup"
 require "cli/app"
diff --git a/fixtures/cli-app/spec/spec_helper.rb b/fixtures/cli-app/spec/spec_helper.rb
index 9d67aac75..b8b3e7bec 100644
--- a/fixtures/cli-app/spec/spec_helper.rb
+++ b/fixtures/cli-app/spec/spec_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH.unshift File.expand_path("../lib", __dir__)
 
 require "cli/app"
diff --git a/fixtures/cli-app/spec/support/aruba.rb b/fixtures/cli-app/spec/support/aruba.rb
index 599d12586..c3219676d 100644
--- a/fixtures/cli-app/spec/support/aruba.rb
+++ b/fixtures/cli-app/spec/support/aruba.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 require "aruba/rspec"
diff --git a/fixtures/empty-app/Rakefile b/fixtures/empty-app/Rakefile
index 29955274e..5263b5839 100644
--- a/fixtures/empty-app/Rakefile
+++ b/fixtures/empty-app/Rakefile
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 require "bundler/gem_tasks"
diff --git a/fixtures/empty-app/cli-app.gemspec b/fixtures/empty-app/cli-app.gemspec
index de89868fb..511e69af2 100644
--- a/fixtures/empty-app/cli-app.gemspec
+++ b/fixtures/empty-app/cli-app.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 lib = File.expand_path("lib", __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require "cli/app/version"
diff --git a/fixtures/empty-app/lib/cli/app.rb b/fixtures/empty-app/lib/cli/app.rb
index f46bb8946..9c3e322b7 100644
--- a/fixtures/empty-app/lib/cli/app.rb
+++ b/fixtures/empty-app/lib/cli/app.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "cli/app/version"
 
 module Cli
diff --git a/fixtures/empty-app/lib/cli/app/version.rb b/fixtures/empty-app/lib/cli/app/version.rb
index f2f5d822d..69e6983ae 100644
--- a/fixtures/empty-app/lib/cli/app/version.rb
+++ b/fixtures/empty-app/lib/cli/app/version.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 module Cli
   module App
-    VERSION = "0.1.0".freeze
+    VERSION = "0.1.0"
   end
 end
diff --git a/fixtures/getting-started-app/Gemfile b/fixtures/getting-started-app/Gemfile
index b954be0d1..f0ad83604 100644
--- a/fixtures/getting-started-app/Gemfile
+++ b/fixtures/getting-started-app/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
 gem "aruba", path: File.expand_path("../../..", __dir__)
diff --git a/fixtures/getting-started-app/features/support/env.rb b/fixtures/getting-started-app/features/support/env.rb
index ba5a3303d..25a3b5d1d 100644
--- a/fixtures/getting-started-app/features/support/env.rb
+++ b/fixtures/getting-started-app/features/support/env.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 require "aruba/cucumber"
diff --git a/gemfiles/cucumber_8.gemfile b/gemfiles/cucumber_8.gemfile
index b8f54b2d6..1a63a295e 100644
--- a/gemfiles/cucumber_8.gemfile
+++ b/gemfiles/cucumber_8.gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file was generated by Appraisal
 
 source "https://rubygems.org"
diff --git a/gemfiles/cucumber_9.gemfile b/gemfiles/cucumber_9.gemfile
index 37a55d72e..99d460de6 100644
--- a/gemfiles/cucumber_9.gemfile
+++ b/gemfiles/cucumber_9.gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file was generated by Appraisal
 
 source "https://rubygems.org"
diff --git a/lib/aruba.rb b/lib/aruba.rb
index dd3a11133..e4afa9406 100644
--- a/lib/aruba.rb
+++ b/lib/aruba.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 require "aruba/api"
diff --git a/lib/aruba/api.rb b/lib/aruba/api.rb
index e73620910..1fc2b4299 100644
--- a/lib/aruba/api.rb
+++ b/lib/aruba/api.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rspec/expectations"
 require "shellwords"
 
diff --git a/lib/aruba/api/bundler.rb b/lib/aruba/api/bundler.rb
index 64dc3f04e..50e4e2e0c 100644
--- a/lib/aruba/api/bundler.rb
+++ b/lib/aruba/api/bundler.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/api/environment"
 require "bundler"
 
diff --git a/lib/aruba/api/commands.rb b/lib/aruba/api/commands.rb
index b2a5fadc0..3273f3ca2 100644
--- a/lib/aruba/api/commands.rb
+++ b/lib/aruba/api/commands.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "pathname"
 
 require "aruba/platform"
diff --git a/lib/aruba/api/core.rb b/lib/aruba/api/core.rb
index 43f22d3b4..f16976e78 100644
--- a/lib/aruba/api/core.rb
+++ b/lib/aruba/api/core.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rspec/expectations"
 require "aruba/runtime"
 require "aruba/errors"
diff --git a/lib/aruba/api/environment.rb b/lib/aruba/api/environment.rb
index 25c638263..42bf28bc8 100644
--- a/lib/aruba/api/environment.rb
+++ b/lib/aruba/api/environment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/platform"
 
 # Aruba
diff --git a/lib/aruba/api/filesystem.rb b/lib/aruba/api/filesystem.rb
index 697c03d0a..4f2593be3 100644
--- a/lib/aruba/api/filesystem.rb
+++ b/lib/aruba/api/filesystem.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "pathname"
 
 require "aruba/platform"
diff --git a/lib/aruba/api/text.rb b/lib/aruba/api/text.rb
index da600d59f..9aa837578 100644
--- a/lib/aruba/api/text.rb
+++ b/lib/aruba/api/text.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Api
diff --git a/lib/aruba/aruba_logger.rb b/lib/aruba/aruba_logger.rb
index 0fe190c3b..4cc792ba8 100644
--- a/lib/aruba/aruba_logger.rb
+++ b/lib/aruba/aruba_logger.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "logger"
 
 # Aruba
diff --git a/lib/aruba/aruba_path.rb b/lib/aruba/aruba_path.rb
index 40fb52787..d32af22de 100644
--- a/lib/aruba/aruba_path.rb
+++ b/lib/aruba/aruba_path.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "pathname"
 
 # Aruba
diff --git a/lib/aruba/basic_configuration.rb b/lib/aruba/basic_configuration.rb
index f99a701e7..2f2577412 100644
--- a/lib/aruba/basic_configuration.rb
+++ b/lib/aruba/basic_configuration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "contracts"
 require "aruba/basic_configuration/option"
 require "aruba/in_config_wrapper"
diff --git a/lib/aruba/basic_configuration/option.rb b/lib/aruba/basic_configuration/option.rb
index 2b8b15e53..f5a0b0c28 100644
--- a/lib/aruba/basic_configuration/option.rb
+++ b/lib/aruba/basic_configuration/option.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Basic Configuration
diff --git a/lib/aruba/cli.rb b/lib/aruba/cli.rb
index 975e189dc..241229a35 100644
--- a/lib/aruba/cli.rb
+++ b/lib/aruba/cli.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "thor"
 require "aruba/console"
 require "aruba/initializer"
diff --git a/lib/aruba/colorizer.rb b/lib/aruba/colorizer.rb
index fc479c68d..aac758616 100644
--- a/lib/aruba/colorizer.rb
+++ b/lib/aruba/colorizer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Simple colorizer class. Only supports the color cyan
diff --git a/lib/aruba/command.rb b/lib/aruba/command.rb
index 6024af628..e60db47d8 100644
--- a/lib/aruba/command.rb
+++ b/lib/aruba/command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "delegate"
 require "aruba/processes/spawn_process"
 require "aruba/processes/in_process"
diff --git a/lib/aruba/command_monitor.rb b/lib/aruba/command_monitor.rb
index ed87e4971..2ac19e5a0 100644
--- a/lib/aruba/command_monitor.rb
+++ b/lib/aruba/command_monitor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/errors"
 
 # Aruba
@@ -96,7 +98,7 @@ def clear
     def all_stdout
       registered_commands.each(&:stop)
 
-      registered_commands.each_with_object("") { |e, a| a << e.stdout }
+      registered_commands.map(&:stdout).join
     end
 
     # Get stderr of all commands
@@ -106,7 +108,7 @@ def all_stdout
     def all_stderr
       registered_commands.each(&:stop)
 
-      registered_commands.each_with_object("") { |e, a| a << e.stderr }
+      registered_commands.map(&:stderr).join
     end
 
     # Get stderr and stdout of all commands
diff --git a/lib/aruba/config/jruby.rb b/lib/aruba/config/jruby.rb
index dbe4d41b6..86fc597b8 100644
--- a/lib/aruba/config/jruby.rb
+++ b/lib/aruba/config/jruby.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rbconfig"
 
 # ideas taken from: http://blog.headius.com/2010/03/jruby-startup-time-tips.html
diff --git a/lib/aruba/config_wrapper.rb b/lib/aruba/config_wrapper.rb
index 361fcbe3d..492bdfd91 100644
--- a/lib/aruba/config_wrapper.rb
+++ b/lib/aruba/config_wrapper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Aruba
   # This wraps the current runtime configuration of aruba.
   # If an option is changed, it notifies the event queue.
diff --git a/lib/aruba/configuration.rb b/lib/aruba/configuration.rb
index 7b1a57b26..61f985b49 100644
--- a/lib/aruba/configuration.rb
+++ b/lib/aruba/configuration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "contracts"
 
 require "aruba/version"
diff --git a/lib/aruba/console.rb b/lib/aruba/console.rb
index 3bd200ce5..0f44bcaaf 100644
--- a/lib/aruba/console.rb
+++ b/lib/aruba/console.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "irb"
 
 require "aruba/api"
diff --git a/lib/aruba/console/help.rb b/lib/aruba/console/help.rb
index e582182ed..052bf8cc7 100644
--- a/lib/aruba/console/help.rb
+++ b/lib/aruba/console/help.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/api"
 
 # Aruba
diff --git a/lib/aruba/contracts/absolute_path.rb b/lib/aruba/contracts/absolute_path.rb
index 4ac6319ab..a72c06382 100644
--- a/lib/aruba/contracts/absolute_path.rb
+++ b/lib/aruba/contracts/absolute_path.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/platform"
 
 # Aruba
diff --git a/lib/aruba/contracts/enum.rb b/lib/aruba/contracts/enum.rb
index 4157ab26c..044478334 100644
--- a/lib/aruba/contracts/enum.rb
+++ b/lib/aruba/contracts/enum.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "contracts"
 
 # Aruba
diff --git a/lib/aruba/contracts/is_power_of_two.rb b/lib/aruba/contracts/is_power_of_two.rb
index 634857aba..13864ca9b 100644
--- a/lib/aruba/contracts/is_power_of_two.rb
+++ b/lib/aruba/contracts/is_power_of_two.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/aruba_path"
 
 # Aruba
diff --git a/lib/aruba/contracts/relative_path.rb b/lib/aruba/contracts/relative_path.rb
index 75713c9e7..034111740 100644
--- a/lib/aruba/contracts/relative_path.rb
+++ b/lib/aruba/contracts/relative_path.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/platform"
 
 # Aruba
diff --git a/lib/aruba/cucumber.rb b/lib/aruba/cucumber.rb
index 78a821a9b..e179847f7 100644
--- a/lib/aruba/cucumber.rb
+++ b/lib/aruba/cucumber.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/version"
 
 require "aruba/api"
diff --git a/lib/aruba/cucumber/command.rb b/lib/aruba/cucumber/command.rb
index 085cd1993..a06bb2754 100644
--- a/lib/aruba/cucumber/command.rb
+++ b/lib/aruba/cucumber/command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/generators/script_file"
 
 When(/^I run `([^`]*)`$/) do |cmd|
@@ -88,7 +90,7 @@
 When "I wait for output/stdout to contain:" do |expected|
   Timeout.timeout(aruba.config.exit_timeout) do
     loop do
-      output = last_command_started.public_send :stdout, wait_for_io: 0
+      output = last_command_started.stdout wait_for_io: 0
 
       output   = sanitize_text(output)
       expected = sanitize_text(expected)
@@ -103,7 +105,7 @@
 When "I wait for output/stdout to contain {string}" do |expected|
   Timeout.timeout(aruba.config.exit_timeout) do
     loop do
-      output = last_command_started.public_send :stdout, wait_for_io: 0
+      output = last_command_started.stdout wait_for_io: 0
 
       output   = sanitize_text(output)
       expected = sanitize_text(expected)
diff --git a/lib/aruba/cucumber/environment.rb b/lib/aruba/cucumber/environment.rb
index 4afeb8b7f..db82fb63b 100644
--- a/lib/aruba/cucumber/environment.rb
+++ b/lib/aruba/cucumber/environment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Given(/^a mocked home directory$/) do
   set_environment_variable "HOME", expand_path(".")
 end
diff --git a/lib/aruba/cucumber/file.rb b/lib/aruba/cucumber/file.rb
index 22a667c43..cf0d6be3c 100644
--- a/lib/aruba/cucumber/file.rb
+++ b/lib/aruba/cucumber/file.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Given(/^I use (?:a|the) fixture(?: named)? "([^"]*)"$/) do |name|
   copy File.join(aruba.config.fixtures_path_prefix, name), name
   cd name
diff --git a/lib/aruba/cucumber/hooks.rb b/lib/aruba/cucumber/hooks.rb
index fd6dea551..54f5eb804 100644
--- a/lib/aruba/cucumber/hooks.rb
+++ b/lib/aruba/cucumber/hooks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/aruba_path"
 require "aruba/api"
 require "aruba/platform"
diff --git a/lib/aruba/cucumber/parameter_types.rb b/lib/aruba/cucumber/parameter_types.rb
index d744d7ad0..e11ff543b 100644
--- a/lib/aruba/cucumber/parameter_types.rb
+++ b/lib/aruba/cucumber/parameter_types.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 ParameterType(name: "channel", regexp: "output|stderr|stdout", transformer: ->(name) { name })
diff --git a/lib/aruba/cucumber/testing_frameworks.rb b/lib/aruba/cucumber/testing_frameworks.rb
index eb1493e29..ded7cd1a5 100644
--- a/lib/aruba/cucumber/testing_frameworks.rb
+++ b/lib/aruba/cucumber/testing_frameworks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Cucumber
 Then(/^the feature(?:s)? should not(?: all)? pass$/) do
   step 'the output should contain " failed)"'
diff --git a/lib/aruba/errors.rb b/lib/aruba/errors.rb
index c0043e9e3..04d059003 100644
--- a/lib/aruba/errors.rb
+++ b/lib/aruba/errors.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Aruba
   # Standard error
   class Error < StandardError; end
diff --git a/lib/aruba/event_bus.rb b/lib/aruba/event_bus.rb
index 219fa20b6..b6ed34b59 100644
--- a/lib/aruba/event_bus.rb
+++ b/lib/aruba/event_bus.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/event_bus/name_resolver"
 require "aruba/errors"
 
diff --git a/lib/aruba/event_bus/name_resolver.rb b/lib/aruba/event_bus/name_resolver.rb
index 4c3ba386b..5c6966058 100644
--- a/lib/aruba/event_bus/name_resolver.rb
+++ b/lib/aruba/event_bus/name_resolver.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/errors"
 
 # Event notification library
diff --git a/lib/aruba/events.rb b/lib/aruba/events.rb
index 123465195..903644875 100644
--- a/lib/aruba/events.rb
+++ b/lib/aruba/events.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Events
diff --git a/lib/aruba/file_size.rb b/lib/aruba/file_size.rb
index 39ee32bd3..5b0a7f7e4 100644
--- a/lib/aruba/file_size.rb
+++ b/lib/aruba/file_size.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "delegate"
 
 # Aruba
diff --git a/lib/aruba/generators/script_file.rb b/lib/aruba/generators/script_file.rb
index ccc36a3fe..3c4cc5bb1 100644
--- a/lib/aruba/generators/script_file.rb
+++ b/lib/aruba/generators/script_file.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Generate script files on command line
diff --git a/lib/aruba/hooks.rb b/lib/aruba/hooks.rb
index dc07fa3da..9e34b8538 100644
--- a/lib/aruba/hooks.rb
+++ b/lib/aruba/hooks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Aruba Hooks
diff --git a/lib/aruba/in_config_wrapper.rb b/lib/aruba/in_config_wrapper.rb
index b13db5d9f..49b447473 100644
--- a/lib/aruba/in_config_wrapper.rb
+++ b/lib/aruba/in_config_wrapper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # In config wrapper
diff --git a/lib/aruba/initializer.rb b/lib/aruba/initializer.rb
index b175499eb..1a816e493 100644
--- a/lib/aruba/initializer.rb
+++ b/lib/aruba/initializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "thor/group"
 require "thor/actions"
 
diff --git a/lib/aruba/matchers/base/message_indenter.rb b/lib/aruba/matchers/base/message_indenter.rb
index 623df5f09..91dd50731 100644
--- a/lib/aruba/matchers/base/message_indenter.rb
+++ b/lib/aruba/matchers/base/message_indenter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Aruba
   module Matchers
     module Base
diff --git a/lib/aruba/matchers/command.rb b/lib/aruba/matchers/command.rb
index c7d017afc..0ce27b869 100644
--- a/lib/aruba/matchers/command.rb
+++ b/lib/aruba/matchers/command.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 Aruba.platform.require_matching_files("../command/**/*.rb", __FILE__)
diff --git a/lib/aruba/matchers/command/be_successfully_executed.rb b/lib/aruba/matchers/command/be_successfully_executed.rb
index 9a27970ab..f746dd59b 100644
--- a/lib/aruba/matchers/command/be_successfully_executed.rb
+++ b/lib/aruba/matchers/command/be_successfully_executed.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/matchers/command/have_exit_status"
 require "aruba/matchers/command/have_finished_in_time"
 
diff --git a/lib/aruba/matchers/command/have_exit_status.rb b/lib/aruba/matchers/command/have_exit_status.rb
index d3ff196c2..c7c206b90 100644
--- a/lib/aruba/matchers/command/have_exit_status.rb
+++ b/lib/aruba/matchers/command/have_exit_status.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method have_exit_status(status)
 #   This matchers checks if <command> has exit status <status>
 #
diff --git a/lib/aruba/matchers/command/have_finished_in_time.rb b/lib/aruba/matchers/command/have_finished_in_time.rb
index 5c4639e7a..efcad090d 100644
--- a/lib/aruba/matchers/command/have_finished_in_time.rb
+++ b/lib/aruba/matchers/command/have_finished_in_time.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method run_too_long
 #   This matchers checks if <command> run too long. Say the timeout is 10
 #   seconds and it takes <command> to finish in 15. This matchers will succeed.
diff --git a/lib/aruba/matchers/command/have_output.rb b/lib/aruba/matchers/command/have_output.rb
index 21e6a23d8..f6cdf70e6 100644
--- a/lib/aruba/matchers/command/have_output.rb
+++ b/lib/aruba/matchers/command/have_output.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/matchers/base/message_indenter"
 
 # @!method have_output
diff --git a/lib/aruba/matchers/command/have_output_on_stderr.rb b/lib/aruba/matchers/command/have_output_on_stderr.rb
index 955808bfa..fc0cde75e 100644
--- a/lib/aruba/matchers/command/have_output_on_stderr.rb
+++ b/lib/aruba/matchers/command/have_output_on_stderr.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method have_output_on_stderr
 #   This matchers checks if <command> has created output on stderr
 #
diff --git a/lib/aruba/matchers/command/have_output_on_stdout.rb b/lib/aruba/matchers/command/have_output_on_stdout.rb
index 30c6206b9..d8108cb8e 100644
--- a/lib/aruba/matchers/command/have_output_on_stdout.rb
+++ b/lib/aruba/matchers/command/have_output_on_stdout.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method have_output_on_stdout
 #   This matchers checks if <command> has created output on stdout
 #
diff --git a/lib/aruba/matchers/command/have_output_size.rb b/lib/aruba/matchers/command/have_output_size.rb
index 528ca5fe3..efc30b721 100644
--- a/lib/aruba/matchers/command/have_output_size.rb
+++ b/lib/aruba/matchers/command/have_output_size.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method have_output_size(output)
 #   This matchers checks if output has size.
 #
diff --git a/lib/aruba/matchers/directory.rb b/lib/aruba/matchers/directory.rb
index 141e0d1c4..82c93eb37 100644
--- a/lib/aruba/matchers/directory.rb
+++ b/lib/aruba/matchers/directory.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 Aruba.platform.require_matching_files("../directory/**/*.rb", __FILE__)
diff --git a/lib/aruba/matchers/directory/be_an_existing_directory.rb b/lib/aruba/matchers/directory/be_an_existing_directory.rb
index 470f952eb..a7ba61c8b 100644
--- a/lib/aruba/matchers/directory/be_an_existing_directory.rb
+++ b/lib/aruba/matchers/directory/be_an_existing_directory.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method be_an_existing_directory
 #   This matchers checks if <directory> exists in filesystem
 #
diff --git a/lib/aruba/matchers/directory/have_sub_directory.rb b/lib/aruba/matchers/directory/have_sub_directory.rb
index 11edad7bf..2c8f0b544 100644
--- a/lib/aruba/matchers/directory/have_sub_directory.rb
+++ b/lib/aruba/matchers/directory/have_sub_directory.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method have_sub_directory(sub_directory)
 #   This matchers checks if <directory> has given sub-directory
 #
diff --git a/lib/aruba/matchers/environment.rb b/lib/aruba/matchers/environment.rb
index 9b0aa5199..78e9c7626 100644
--- a/lib/aruba/matchers/environment.rb
+++ b/lib/aruba/matchers/environment.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 Aruba.platform.require_matching_files("../matchers/environment/*.rb", __FILE__)
diff --git a/lib/aruba/matchers/file.rb b/lib/aruba/matchers/file.rb
index 4fcba032d..b92a6a101 100644
--- a/lib/aruba/matchers/file.rb
+++ b/lib/aruba/matchers/file.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 Aruba.platform.require_matching_files("../file/**/*.rb", __FILE__)
diff --git a/lib/aruba/matchers/file/be_a_command_found_in_path.rb b/lib/aruba/matchers/file/be_a_command_found_in_path.rb
index 91d2b2219..2896af961 100644
--- a/lib/aruba/matchers/file/be_a_command_found_in_path.rb
+++ b/lib/aruba/matchers/file/be_a_command_found_in_path.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method be_a_command_found_in_path
 #   This matchers checks if <command> can be found in path
 #
diff --git a/lib/aruba/matchers/file/be_an_existing_executable.rb b/lib/aruba/matchers/file/be_an_existing_executable.rb
index f7c926ac0..94ad408ec 100644
--- a/lib/aruba/matchers/file/be_an_existing_executable.rb
+++ b/lib/aruba/matchers/file/be_an_existing_executable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "shellwords"
 
 # @!method be_an_existing_executable
diff --git a/lib/aruba/matchers/file/be_an_existing_file.rb b/lib/aruba/matchers/file/be_an_existing_file.rb
index e94b8a9da..406a6589e 100644
--- a/lib/aruba/matchers/file/be_an_existing_file.rb
+++ b/lib/aruba/matchers/file/be_an_existing_file.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method be_an_existing_file
 #   This matchers checks if <file> exists in filesystem
 #
diff --git a/lib/aruba/matchers/file/have_file_content.rb b/lib/aruba/matchers/file/have_file_content.rb
index d0dd4657f..36d152f73 100644
--- a/lib/aruba/matchers/file/have_file_content.rb
+++ b/lib/aruba/matchers/file/have_file_content.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method have_file_content(content)
 #   This matchers checks if <file> has content. `content` can be a string,
 #   regexp or an RSpec matcher.
diff --git a/lib/aruba/matchers/file/have_file_size.rb b/lib/aruba/matchers/file/have_file_size.rb
index 18ff69a64..0d926498b 100644
--- a/lib/aruba/matchers/file/have_file_size.rb
+++ b/lib/aruba/matchers/file/have_file_size.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method have_file_size(size)
 #   This matchers checks if path has file size
 #
diff --git a/lib/aruba/matchers/file/have_same_file_content.rb b/lib/aruba/matchers/file/have_same_file_content.rb
index deae016d4..ebbca9989 100644
--- a/lib/aruba/matchers/file/have_same_file_content.rb
+++ b/lib/aruba/matchers/file/have_same_file_content.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "fileutils"
 
 # @!method have_same_file_content_as(file_name)
diff --git a/lib/aruba/matchers/path.rb b/lib/aruba/matchers/path.rb
index e7dc79b08..1ca38942c 100644
--- a/lib/aruba/matchers/path.rb
+++ b/lib/aruba/matchers/path.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 Aruba.platform.require_matching_files("../path/**/*.rb", __FILE__)
diff --git a/lib/aruba/matchers/path/a_path_matching_pattern.rb b/lib/aruba/matchers/path/a_path_matching_pattern.rb
index c2fb0a781..21d95f2b9 100644
--- a/lib/aruba/matchers/path/a_path_matching_pattern.rb
+++ b/lib/aruba/matchers/path/a_path_matching_pattern.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method a_path_matching_pattern(/pattern/)
 #   This matchers checks if <path> matches pattern. `pattern` can be a string,
 #   regexp or an RSpec matcher.
diff --git a/lib/aruba/matchers/path/be_an_absolute_path.rb b/lib/aruba/matchers/path/be_an_absolute_path.rb
index da8dd291e..d31374ba0 100644
--- a/lib/aruba/matchers/path/be_an_absolute_path.rb
+++ b/lib/aruba/matchers/path/be_an_absolute_path.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method be_an_absolute_path
 #   This matchers checks if <path> exists in filesystem
 #
diff --git a/lib/aruba/matchers/path/be_an_existing_path.rb b/lib/aruba/matchers/path/be_an_existing_path.rb
index b455b1fd4..2c7cae3b7 100644
--- a/lib/aruba/matchers/path/be_an_existing_path.rb
+++ b/lib/aruba/matchers/path/be_an_existing_path.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method be_an_existing_path
 #   This matchers checks if <path> exists in filesystem
 #
diff --git a/lib/aruba/matchers/path/have_permissions.rb b/lib/aruba/matchers/path/have_permissions.rb
index 887cc700e..b4a14f6ec 100644
--- a/lib/aruba/matchers/path/have_permissions.rb
+++ b/lib/aruba/matchers/path/have_permissions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method have_permissions(permissions)
 #   This matchers checks if <file> or <directory> has <perm> permissions
 #
diff --git a/lib/aruba/matchers/string.rb b/lib/aruba/matchers/string.rb
index dc6e05da7..b5444ac82 100644
--- a/lib/aruba/matchers/string.rb
+++ b/lib/aruba/matchers/string.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 Aruba.platform.require_matching_files("../string/**/*.rb", __FILE__)
diff --git a/lib/aruba/matchers/string/include_output_string.rb b/lib/aruba/matchers/string/include_output_string.rb
index 18746bce0..245774e6c 100644
--- a/lib/aruba/matchers/string/include_output_string.rb
+++ b/lib/aruba/matchers/string/include_output_string.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method include_output_string(string)
 #   This matchers checks if the output string of a command includes string.
 #
diff --git a/lib/aruba/matchers/string/match_output_string.rb b/lib/aruba/matchers/string/match_output_string.rb
index 221cbf6d6..1f45aa081 100644
--- a/lib/aruba/matchers/string/match_output_string.rb
+++ b/lib/aruba/matchers/string/match_output_string.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method match_output_string(string)
 #   This matchers checks if the output string of a command matches regular expression.
 #
diff --git a/lib/aruba/matchers/string/output_string_eq.rb b/lib/aruba/matchers/string/output_string_eq.rb
index 802dbbaab..dc0e44c43 100644
--- a/lib/aruba/matchers/string/output_string_eq.rb
+++ b/lib/aruba/matchers/string/output_string_eq.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @!method output_string_eq(string)
 #   This matchers checks if the output string of a command includes string.
 #
diff --git a/lib/aruba/platform.rb b/lib/aruba/platform.rb
index 35c550652..f6600fbe0 100644
--- a/lib/aruba/platform.rb
+++ b/lib/aruba/platform.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/platforms/unix_platform"
 require "aruba/platforms/windows_platform"
 
diff --git a/lib/aruba/platforms/announcer.rb b/lib/aruba/platforms/announcer.rb
index d6b061235..2968263f9 100644
--- a/lib/aruba/platforms/announcer.rb
+++ b/lib/aruba/platforms/announcer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "shellwords"
 require "aruba/colorizer"
 
diff --git a/lib/aruba/platforms/aruba_file_creator.rb b/lib/aruba/platforms/aruba_file_creator.rb
index 845e2b532..e4c4f6dee 100644
--- a/lib/aruba/platforms/aruba_file_creator.rb
+++ b/lib/aruba/platforms/aruba_file_creator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Platforms
diff --git a/lib/aruba/platforms/aruba_fixed_size_file_creator.rb b/lib/aruba/platforms/aruba_fixed_size_file_creator.rb
index 37e725c04..6117da083 100644
--- a/lib/aruba/platforms/aruba_fixed_size_file_creator.rb
+++ b/lib/aruba/platforms/aruba_fixed_size_file_creator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Platforms
diff --git a/lib/aruba/platforms/determine_disk_usage.rb b/lib/aruba/platforms/determine_disk_usage.rb
index c5ff99251..ca501e75b 100644
--- a/lib/aruba/platforms/determine_disk_usage.rb
+++ b/lib/aruba/platforms/determine_disk_usage.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/file_size"
 
 module Aruba
diff --git a/lib/aruba/platforms/determine_file_size.rb b/lib/aruba/platforms/determine_file_size.rb
index e9d2c63bc..53027d155 100644
--- a/lib/aruba/platforms/determine_file_size.rb
+++ b/lib/aruba/platforms/determine_file_size.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Platforms
diff --git a/lib/aruba/platforms/filesystem_status.rb b/lib/aruba/platforms/filesystem_status.rb
index 6a6bfddc6..bbc8a9f9d 100644
--- a/lib/aruba/platforms/filesystem_status.rb
+++ b/lib/aruba/platforms/filesystem_status.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Aruba
   module Platforms
     # File System Status object
diff --git a/lib/aruba/platforms/local_environment.rb b/lib/aruba/platforms/local_environment.rb
index 2f5403289..76cdcd229 100644
--- a/lib/aruba/platforms/local_environment.rb
+++ b/lib/aruba/platforms/local_environment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Platforms
diff --git a/lib/aruba/platforms/simple_table.rb b/lib/aruba/platforms/simple_table.rb
index 4650658ba..ffe3c921c 100644
--- a/lib/aruba/platforms/simple_table.rb
+++ b/lib/aruba/platforms/simple_table.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Platforms
diff --git a/lib/aruba/platforms/unix_command_string.rb b/lib/aruba/platforms/unix_command_string.rb
index 6a6d198cf..8f2fdec48 100644
--- a/lib/aruba/platforms/unix_command_string.rb
+++ b/lib/aruba/platforms/unix_command_string.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "delegate"
 require "shellwords"
 
diff --git a/lib/aruba/platforms/unix_environment_variables.rb b/lib/aruba/platforms/unix_environment_variables.rb
index 25a54f507..0d5ed4c37 100644
--- a/lib/aruba/platforms/unix_environment_variables.rb
+++ b/lib/aruba/platforms/unix_environment_variables.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Platforms
diff --git a/lib/aruba/platforms/unix_platform.rb b/lib/aruba/platforms/unix_platform.rb
index 11881c802..03709215c 100644
--- a/lib/aruba/platforms/unix_platform.rb
+++ b/lib/aruba/platforms/unix_platform.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rbconfig"
 require "rubygems"
 require "pathname"
diff --git a/lib/aruba/platforms/unix_which.rb b/lib/aruba/platforms/unix_which.rb
index 0c1de102c..10c298b58 100644
--- a/lib/aruba/platforms/unix_which.rb
+++ b/lib/aruba/platforms/unix_which.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Platforms
diff --git a/lib/aruba/platforms/windows_command_string.rb b/lib/aruba/platforms/windows_command_string.rb
index 0a90f5ceb..316d04b6a 100644
--- a/lib/aruba/platforms/windows_command_string.rb
+++ b/lib/aruba/platforms/windows_command_string.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Platforms
diff --git a/lib/aruba/platforms/windows_environment_variables.rb b/lib/aruba/platforms/windows_environment_variables.rb
index be3af2c35..ffcfe74f9 100644
--- a/lib/aruba/platforms/windows_environment_variables.rb
+++ b/lib/aruba/platforms/windows_environment_variables.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/platforms/unix_environment_variables"
 
 # Aruba
diff --git a/lib/aruba/platforms/windows_platform.rb b/lib/aruba/platforms/windows_platform.rb
index c4c85f268..e4cb0d87c 100644
--- a/lib/aruba/platforms/windows_platform.rb
+++ b/lib/aruba/platforms/windows_platform.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/platforms/unix_platform"
 require "aruba/platforms/windows_command_string"
 require "aruba/platforms/windows_environment_variables"
diff --git a/lib/aruba/platforms/windows_which.rb b/lib/aruba/platforms/windows_which.rb
index 5d6688a0a..6d9fa4545 100644
--- a/lib/aruba/platforms/windows_which.rb
+++ b/lib/aruba/platforms/windows_which.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Aruba
 module Aruba
   # Platforms
diff --git a/lib/aruba/processes/basic_process.rb b/lib/aruba/processes/basic_process.rb
index 148095f16..2a6d1a756 100644
--- a/lib/aruba/processes/basic_process.rb
+++ b/lib/aruba/processes/basic_process.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/platform"
 require "shellwords"
 
diff --git a/lib/aruba/processes/debug_process.rb b/lib/aruba/processes/debug_process.rb
index 5a14130d2..5d28d7dde 100644
--- a/lib/aruba/processes/debug_process.rb
+++ b/lib/aruba/processes/debug_process.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/processes/spawn_process"
 
 # Aruba
diff --git a/lib/aruba/processes/in_process.rb b/lib/aruba/processes/in_process.rb
index 96c332e65..4d63fb432 100644
--- a/lib/aruba/processes/in_process.rb
+++ b/lib/aruba/processes/in_process.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "shellwords"
 require "stringio"
 require "aruba/processes/basic_process"
diff --git a/lib/aruba/processes/spawn_process.rb b/lib/aruba/processes/spawn_process.rb
index db807f481..88f4c207f 100644
--- a/lib/aruba/processes/spawn_process.rb
+++ b/lib/aruba/processes/spawn_process.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "tempfile"
 require "shellwords"
 
diff --git a/lib/aruba/rspec.rb b/lib/aruba/rspec.rb
index 7ab2200a2..198733b0a 100644
--- a/lib/aruba/rspec.rb
+++ b/lib/aruba/rspec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rspec/core"
 
 require "aruba"
diff --git a/lib/aruba/runtime.rb b/lib/aruba/runtime.rb
index 78358e8a1..d975a93ee 100644
--- a/lib/aruba/runtime.rb
+++ b/lib/aruba/runtime.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/configuration"
 require "aruba/aruba_path"
 require "aruba/config_wrapper"
diff --git a/lib/aruba/setup.rb b/lib/aruba/setup.rb
index 720d071f2..2b3eebbed 100644
--- a/lib/aruba/setup.rb
+++ b/lib/aruba/setup.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Aruba
   class Setup
     private
diff --git a/lib/aruba/version.rb b/lib/aruba/version.rb
index 5a7628961..5d0dd697f 100644
--- a/lib/aruba/version.rb
+++ b/lib/aruba/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Aruba
-  VERSION = "2.2.0".freeze
+  VERSION = "2.2.0"
 end
diff --git a/spec/aruba/api/bundler_spec.rb b/spec/aruba/api/bundler_spec.rb
index 46ac3d741..81d4a8dd5 100644
--- a/spec/aruba/api/bundler_spec.rb
+++ b/spec/aruba/api/bundler_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/api"
 
diff --git a/spec/aruba/api/commands_spec.rb b/spec/aruba/api/commands_spec.rb
index 06c9f7776..07828a6d4 100644
--- a/spec/aruba/api/commands_spec.rb
+++ b/spec/aruba/api/commands_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/api"
 require "fileutils"
@@ -11,15 +13,17 @@
 
       after { @aruba.all_commands.each(&:stop) }
 
-      it "respond to input" do
-        @aruba.type "Hello"
-        @aruba.type "\u0004"
+      it "respond to unfrozen input" do
+        @aruba.type(+"Hello")
+        @aruba.type(+"\u0004")
+
         expect(@aruba.last_command_started).to have_output "Hello"
       end
 
       it "respond to frozen input" do
-        @aruba.type "Hello".freeze
-        @aruba.type "\u0004".freeze
+        @aruba.type "Hello"
+        @aruba.type "\u0004"
+
         expect(@aruba.last_command_started).to have_output "Hello"
       end
 
diff --git a/spec/aruba/api/core_spec.rb b/spec/aruba/api/core_spec.rb
index 1e8df29f7..b3a3a6eb9 100644
--- a/spec/aruba/api/core_spec.rb
+++ b/spec/aruba/api/core_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/api"
 require "fileutils"
diff --git a/spec/aruba/api/filesystem_spec.rb b/spec/aruba/api/filesystem_spec.rb
index 88cc626db..b00600b6f 100644
--- a/spec/aruba/api/filesystem_spec.rb
+++ b/spec/aruba/api/filesystem_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/api"
 
diff --git a/spec/aruba/api/runtime_spec.rb b/spec/aruba/api/runtime_spec.rb
index 222e85e7b..70a86e84e 100644
--- a/spec/aruba/api/runtime_spec.rb
+++ b/spec/aruba/api/runtime_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe "aruba" do
diff --git a/spec/aruba/api_spec.rb b/spec/aruba/api_spec.rb
index 2455fe44a..4efd47bde 100644
--- a/spec/aruba/api_spec.rb
+++ b/spec/aruba/api_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/api"
 require "fileutils"
diff --git a/spec/aruba/aruba_path_spec.rb b/spec/aruba/aruba_path_spec.rb
index e73788861..dc604199a 100644
--- a/spec/aruba/aruba_path_spec.rb
+++ b/spec/aruba/aruba_path_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/aruba_path"
 
diff --git a/spec/aruba/basic_configuration_spec.rb b/spec/aruba/basic_configuration_spec.rb
index 871057da3..1f9f3a0a8 100644
--- a/spec/aruba/basic_configuration_spec.rb
+++ b/spec/aruba/basic_configuration_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::BasicConfiguration do
diff --git a/spec/aruba/command_monitor_spec.rb b/spec/aruba/command_monitor_spec.rb
index b08ca8e5b..ffd91f0de 100644
--- a/spec/aruba/command_monitor_spec.rb
+++ b/spec/aruba/command_monitor_spec.rb
@@ -1,21 +1,54 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::CommandMonitor do
   let(:monitor) { described_class.new(announcer: announcer) }
   let(:announcer) { instance_double(Aruba::Platforms::Announcer) }
-  let(:process) { instance_double(Aruba::Processes::BasicProcess, commandline: "foobar") }
+  let(:foo_process) do
+    instance_double(Aruba::Processes::InProcess, commandline: "foo",
+                                                 stop: nil,
+                                                 stdout: "foo_stdout\n",
+                                                 stderr: "foo_stderr\n")
+  end
+  let(:bar_process) do
+    instance_double(Aruba::Processes::InProcess, commandline: "bar",
+                                                 stop: nil,
+                                                 stdout: "bar_stdout\n",
+                                                 stderr: "bar_stderr\n")
+  end
 
   before do
-    monitor.register_command(process)
+    monitor.register_command(foo_process)
+    monitor.register_command(bar_process)
   end
 
   describe "#find" do
     it "find the process with the given name" do
-      expect(monitor.find("foobar")).to eq process
+      expect(monitor.find("foo")).to eq foo_process
     end
 
     it "fails if no process with the given name exists" do
       expect { monitor.find("boofar") }.to raise_error Aruba::CommandNotFoundError
     end
   end
+
+  describe "#all_stdout" do
+    it "combines stdout from all registered processs" do
+      expect(monitor.all_stdout).to eq "foo_stdout\nbar_stdout\n"
+    end
+  end
+
+  describe "#all_stderr" do
+    it "combines stderr from all registered processs" do
+      expect(monitor.all_stderr).to eq "foo_stderr\nbar_stderr\n"
+    end
+  end
+
+  describe "#all_output" do
+    it "combines stdout and stderr from all registered processs" do
+      expect(monitor.all_output)
+        .to eq "foo_stdout\nbar_stdout\nfoo_stderr\nbar_stderr\n"
+    end
+  end
 end
diff --git a/spec/aruba/command_spec.rb b/spec/aruba/command_spec.rb
index 8df16af92..cb3c90ee1 100644
--- a/spec/aruba/command_spec.rb
+++ b/spec/aruba/command_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::Command do
diff --git a/spec/aruba/configuration_spec.rb b/spec/aruba/configuration_spec.rb
index 35e208976..da91bcd9e 100644
--- a/spec/aruba/configuration_spec.rb
+++ b/spec/aruba/configuration_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::Configuration do
diff --git a/spec/aruba/event_bus/name_resolver_spec.rb b/spec/aruba/event_bus/name_resolver_spec.rb
index e81cfc14b..6fedf6512 100644
--- a/spec/aruba/event_bus/name_resolver_spec.rb
+++ b/spec/aruba/event_bus/name_resolver_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 describe Aruba::EventBus::NameResolver do
diff --git a/spec/aruba/event_bus_spec.rb b/spec/aruba/event_bus_spec.rb
index fce01b72d..799c5bfc0 100644
--- a/spec/aruba/event_bus_spec.rb
+++ b/spec/aruba/event_bus_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 describe Aruba::EventBus do
diff --git a/spec/aruba/hooks_spec.rb b/spec/aruba/hooks_spec.rb
index 39f5da7d8..8d5e13a61 100644
--- a/spec/aruba/hooks_spec.rb
+++ b/spec/aruba/hooks_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 describe Aruba::Hooks do
diff --git a/spec/aruba/in_config_wrapper_spec.rb b/spec/aruba/in_config_wrapper_spec.rb
index c4ea95777..ccf6b868e 100644
--- a/spec/aruba/in_config_wrapper_spec.rb
+++ b/spec/aruba/in_config_wrapper_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::InConfigWrapper do
diff --git a/spec/aruba/jruby_spec.rb b/spec/aruba/jruby_spec.rb
index 414dbb9c1..d71c1d6f3 100644
--- a/spec/aruba/jruby_spec.rb
+++ b/spec/aruba/jruby_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/api"
 
diff --git a/spec/aruba/matchers/command/have_output_size_spec.rb b/spec/aruba/matchers/command/have_output_size_spec.rb
index d0adfda00..0ee6fa3d9 100644
--- a/spec/aruba/matchers/command/have_output_size_spec.rb
+++ b/spec/aruba/matchers/command/have_output_size_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe "Output Matchers" do
diff --git a/spec/aruba/matchers/command_spec.rb b/spec/aruba/matchers/command_spec.rb
index 4083d1fab..51275177a 100644
--- a/spec/aruba/matchers/command_spec.rb
+++ b/spec/aruba/matchers/command_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe "Command Matchers" do
diff --git a/spec/aruba/matchers/directory_spec.rb b/spec/aruba/matchers/directory_spec.rb
index 729831783..b61d16bff 100644
--- a/spec/aruba/matchers/directory_spec.rb
+++ b/spec/aruba/matchers/directory_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/matchers/directory"
 require "fileutils"
diff --git a/spec/aruba/matchers/file_spec.rb b/spec/aruba/matchers/file_spec.rb
index 6e003b508..d1e9a4221 100644
--- a/spec/aruba/matchers/file_spec.rb
+++ b/spec/aruba/matchers/file_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/matchers/file"
 
diff --git a/spec/aruba/matchers/path_spec.rb b/spec/aruba/matchers/path_spec.rb
index d463395d0..5898faa2b 100644
--- a/spec/aruba/matchers/path_spec.rb
+++ b/spec/aruba/matchers/path_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 require "fileutils"
diff --git a/spec/aruba/platforms/announcer_spec.rb b/spec/aruba/platforms/announcer_spec.rb
index 7ea45cea9..84db39814 100644
--- a/spec/aruba/platforms/announcer_spec.rb
+++ b/spec/aruba/platforms/announcer_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/platforms/announcer"
 
diff --git a/spec/aruba/platforms/simple_table_spec.rb b/spec/aruba/platforms/simple_table_spec.rb
index a33210255..e9ca67c7e 100644
--- a/spec/aruba/platforms/simple_table_spec.rb
+++ b/spec/aruba/platforms/simple_table_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/platform"
 
diff --git a/spec/aruba/platforms/unix_command_string_spec.rb b/spec/aruba/platforms/unix_command_string_spec.rb
index 7475b43eb..ee5bdb177 100644
--- a/spec/aruba/platforms/unix_command_string_spec.rb
+++ b/spec/aruba/platforms/unix_command_string_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::Platforms::UnixCommandString do
diff --git a/spec/aruba/platforms/unix_platform_spec.rb b/spec/aruba/platforms/unix_platform_spec.rb
index 75718f726..53e74c2df 100644
--- a/spec/aruba/platforms/unix_platform_spec.rb
+++ b/spec/aruba/platforms/unix_platform_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/platforms/unix_platform"
 
diff --git a/spec/aruba/platforms/windows_command_string_spec.rb b/spec/aruba/platforms/windows_command_string_spec.rb
index 07f52b781..582d6beea 100644
--- a/spec/aruba/platforms/windows_command_string_spec.rb
+++ b/spec/aruba/platforms/windows_command_string_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::Platforms::WindowsCommandString do
diff --git a/spec/aruba/platforms/windows_environment_variables_spec.rb b/spec/aruba/platforms/windows_environment_variables_spec.rb
index c7868358e..7baa2b3d8 100644
--- a/spec/aruba/platforms/windows_environment_variables_spec.rb
+++ b/spec/aruba/platforms/windows_environment_variables_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/platforms/windows_environment_variables"
 
diff --git a/spec/aruba/platforms/windows_platform_spec.rb b/spec/aruba/platforms/windows_platform_spec.rb
index 5ae02e8ab..699eac35b 100644
--- a/spec/aruba/platforms/windows_platform_spec.rb
+++ b/spec/aruba/platforms/windows_platform_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 require "aruba/platforms/windows_platform"
 
diff --git a/spec/aruba/processes/basic_process_spec.rb b/spec/aruba/processes/basic_process_spec.rb
index 0311c0092..dcc6637b6 100644
--- a/spec/aruba/processes/basic_process_spec.rb
+++ b/spec/aruba/processes/basic_process_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::Processes::BasicProcess do
@@ -6,7 +8,7 @@
       def initialize(*args)
         @stdout = args.shift
         @stderr = args.shift
-        super(*args)
+        super
       end
 
       def stdout(*_args)
diff --git a/spec/aruba/processes/in_process_spec.rb b/spec/aruba/processes/in_process_spec.rb
index ca275084d..dd87e9144 100644
--- a/spec/aruba/processes/in_process_spec.rb
+++ b/spec/aruba/processes/in_process_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::Processes::InProcess do
diff --git a/spec/aruba/processes/spawn_process_spec.rb b/spec/aruba/processes/spawn_process_spec.rb
index a3aa03999..1bcdcb978 100644
--- a/spec/aruba/processes/spawn_process_spec.rb
+++ b/spec/aruba/processes/spawn_process_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::Processes::SpawnProcess do
diff --git a/spec/aruba/rspec_spec.rb b/spec/aruba/rspec_spec.rb
index 4db4ff1d0..078a53335 100644
--- a/spec/aruba/rspec_spec.rb
+++ b/spec/aruba/rspec_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe "RSpec Integration", type: :aruba do
diff --git a/spec/aruba/runtime_spec.rb b/spec/aruba/runtime_spec.rb
index 43b1303f9..f3c46497c 100644
--- a/spec/aruba/runtime_spec.rb
+++ b/spec/aruba/runtime_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "spec_helper"
 
 RSpec.describe Aruba::Runtime do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index bf0b5fdde..7156b79fe 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH << File.expand_path("../lib", __dir__)
 
 unless RUBY_PLATFORM.include?("java")
diff --git a/spec/support/configs/aruba.rb b/spec/support/configs/aruba.rb
index 83175bb45..b1c207f72 100644
--- a/spec/support/configs/aruba.rb
+++ b/spec/support/configs/aruba.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "aruba/rspec"
 require "aruba/config/jruby"
 
diff --git a/spec/support/configs/pry.rb b/spec/support/configs/pry.rb
index bd4895bbf..f460211a8 100644
--- a/spec/support/configs/pry.rb
+++ b/spec/support/configs/pry.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Otherwise pry doesn't find it's RC file
 # if ENV['HOME'] is mocked
 ENV["PRYRC"] = File.expand_path("~/.pryrc")
diff --git a/spec/support/configs/rspec.rb b/spec/support/configs/rspec.rb
index 8014aa1c4..eb4188c66 100644
--- a/spec/support/configs/rspec.rb
+++ b/spec/support/configs/rspec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rspec/core"
 require "aruba/api"
 
diff --git a/spec/support/helpers/reporting.rb b/spec/support/helpers/reporting.rb
index 3788635ba..23d57c118 100644
--- a/spec/support/helpers/reporting.rb
+++ b/spec/support/helpers/reporting.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module SpecHelpers
   module Reporting
     # Captures the given stream and returns it:
diff --git a/spec/support/shared_contexts/aruba.rb b/spec/support/shared_contexts/aruba.rb
index d7889547b..b321c322f 100644
--- a/spec/support/shared_contexts/aruba.rb
+++ b/spec/support/shared_contexts/aruba.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "fileutils"
 require "securerandom"
 
diff --git a/spec/support/shared_examples/configuration.rb b/spec/support/shared_examples/configuration.rb
index 6cad2fc91..dab801f50 100644
--- a/spec/support/shared_examples/configuration.rb
+++ b/spec/support/shared_examples/configuration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 RSpec.shared_examples "a basic configuration" do
   subject(:config) do
     Class.new(described_class) do