diff --git a/.travis.yml b/.travis.yml
index 0ea6dcb5..cb130629 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,9 +5,13 @@ notifications:
   email: false
 rvm:
 - 2.3.0
-- 2.2
-- 2.1
+- 2.2.2
 - jruby-9.0.3.0
+- jruby-9.0.4.0
+- jruby-9.0.5.0
+- jruby-9.1.0.0
+- jruby-9.1.1.0
+- jruby-9.1.2.0
 before_install:
 - echo '--colour' > ~/.rspec
 - 'echo ''gem: --no-document'' > ~/.gemrc'
@@ -19,3 +23,5 @@ env:
 gemfile:
   - gemfiles/4.1.gemfile
   - gemfiles/4.2.gemfile
+  - gemfiles/5.0.0.gemfile
+  - gemfiles/master.gemfile
diff --git a/Appraisals b/Appraisals
index ba0f768d..2cd7413f 100644
--- a/Appraisals
+++ b/Appraisals
@@ -1,7 +1,3 @@
-appraise "3.2" do
-  gem "rails", git: "https://github.com/rails/rails.git", branch: "3-2-stable"
-end
-
 appraise "4.1" do
   gem "rails", "~> 4.1.1"
 end
@@ -9,3 +5,11 @@ end
 appraise "4.2" do
   gem "rails", "~> 4.2.1"
 end
+
+appraise "5.0.0" do
+  gem "rails", "5.0.0"
+end
+
+appraise "master" do
+  gem "rails", git: "https://github.com/rails/rails.git", branch: "master"
+end
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2bc2d79b..bbd30d76 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,9 @@
 master
 ------
 
+* `EmberCli::EmberController` now inherits from `ActionController::Base` instead
+  of `ApplicationController`. [#400]
+* Remove support for Ruby 2.1.x. [#400]
 * Don't route requests to `/rails/info` through the mounted Ember application.
 
 0.7.4
@@ -33,6 +36,7 @@ master
 * `EmberCli::Deploy::File` serves assets with Rails' `static_cache_control`
   value. [#403]
 
+[#400]: https://github.com/thoughtbot/ember-cli-rails/pull/400
 [#396]: https://github.com/thoughtbot/ember-cli-rails/pull/396
 [#403]: https://github.com/thoughtbot/ember-cli-rails/pull/403
 
diff --git a/Gemfile b/Gemfile
index 6e587d71..1232bfdb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,9 +6,13 @@ gem "appraisal"
 gem "rails", "4.2.4"
 gem "pry"
 
+if RUBY_ENGINE == "jruby"
+  gem "json-jruby"
+end
+
 group :development, :test do
-  gem "high_voltage", "~> 2.4.0"
-  gem "rspec-rails", "~> 3.3.0"
+  gem "high_voltage", "~> 3.0.0"
+  gem "rspec-rails", "~> 3.5.0"
 end
 
 group :test do
diff --git a/README.md b/README.md
index 0f781a73..2ba8e600 100644
--- a/README.md
+++ b/README.md
@@ -630,7 +630,7 @@ This project supports:
 
 This project supports:
 
-* Ruby versions `>= 2.1.0`
+* Ruby versions `>= 2.2.0`
 * Rails versions `>=4.1.x`.
 
 To learn more about supported versions and upgrades, read the [upgrading guide].
diff --git a/UPGRADING.md b/UPGRADING.md
index 0c75a49c..80c7a1a4 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -8,6 +8,12 @@ Additionally, this codebase makes use of [(required) keyword arguments][kwargs].
 From `ember-cli-rails@0.4.0` and on, we will no longer support versions of Ruby
 prior to `2.1.0`.
 
+`ember-cli-rails@0.8.0` adds support for Rails 5, which depends on `rack@2.0.x`,
+which **requires** Ruby `2.2.2` or greater.
+
+From `ember-cli-rails@0.8.0` and on, we will no longer support versions of Ruby
+prior to `2.2.2`.
+
 To use `ember-cli-rails` with older versions of Ruby, try the `0.3.x` series.
 
 [kwargs]: https://robots.thoughtbot.com/ruby-2-keyword-arguments
diff --git a/app/controller/ember_cli/ember_controller.rb b/app/controller/ember_cli/ember_controller.rb
index 7c6835f9..24e21cbb 100644
--- a/app/controller/ember_cli/ember_controller.rb
+++ b/app/controller/ember_cli/ember_controller.rb
@@ -3,10 +3,5 @@ class EmberController < ::ApplicationController
     def index
       render layout: false
     end
-
-    def ember_app
-      params[:ember_app]
-    end
-    helper_method :ember_app
   end
 end
diff --git a/app/helpers/ember_rails_helper.rb b/app/helpers/ember_rails_helper.rb
index e145b3ae..1560c8ad 100644
--- a/app/helpers/ember_rails_helper.rb
+++ b/app/helpers/ember_rails_helper.rb
@@ -8,6 +8,6 @@ def render_ember_app(name, &block)
 
     head, body = markup_capturer.capture
 
-    render html: EmberCli[name].index_html(head: head, body: body).html_safe
+    render text: EmberCli[name].index_html(head: head, body: body).html_safe
   end
 end
diff --git a/app/views/ember_cli/ember/index.html.erb b/app/views/ember_cli/ember/index.html.erb
index 6004b207..8ce344e4 100644
--- a/app/views/ember_cli/ember/index.html.erb
+++ b/app/views/ember_cli/ember/index.html.erb
@@ -1,4 +1,4 @@
-<%= render_ember_app ember_app do |head| %>
+<%= render_ember_app params[:ember_app] do |head| %>
   <% head.append do %>
     <%= csrf_meta_tags %>
   <% end %>
diff --git a/bin/clean b/bin/clean
index 2bf7899b..96c6f547 100755
--- a/bin/clean
+++ b/bin/clean
@@ -2,4 +2,4 @@
 
 set -e
 
-rm -rf spec/dummy/my-app
+rm -rf spec/dummy/{my-app,tmp}
diff --git a/bin/setup b/bin/setup
index 6c17f614..f66d0f85 100755
--- a/bin/setup
+++ b/bin/setup
@@ -13,21 +13,6 @@ if ! command -v bower > /dev/null; then
   npm install -g bower
 fi
 
-if ! [ -d spec/dummy/my-app ]; then
-  git clone https://github.com/ember-cli/ember-new-output.git spec/dummy/my-app
+bin/setup_ember spec/dummy/my-app
 
-  bin/setup_ember
-fi
-
-# Only if this isn't CI
-if [ -z "$CI" ]; then
-  bin/appraisal install
-fi
-
-root="$(pwd)"
-
-cd ${root}/spec/dummy/my-app &&
-  npm install --save-dev ember-cli-rails-addon@rondale-sc/ember-cli-rails-addon
-  bower install
-
-cd ${root}/spec/dummy && bundle exec rake ember:install
+cd spec/dummy && bundle exec rake ember:install
diff --git a/bin/setup_ember b/bin/setup_ember
index 84463ca9..724d8975 100755
--- a/bin/setup_ember
+++ b/bin/setup_ember
@@ -2,13 +2,25 @@
 
 set -e
 
-# make router catchall routes
-sed -i -e 's/auto/hash/' spec/dummy/my-app/config/environment.js
+setup_ember() {
+  local target="${1-spec/dummy/my-app}"
 
-# add text to a template
-echo 'Welcome to Ember' >> spec/dummy/my-app/app/templates/application.hbs
+  if ! [ -d $target ]; then
+    git clone -b stable https://github.com/ember-cli/ember-new-output.git $target
 
-# add an image to a template
-echo '<img src="assets/logo.png">' >> spec/dummy/my-app/app/templates/application.hbs
-mkdir -p spec/dummy/my-app/public/assets
-cp spec/fixtures/logo.png spec/dummy/my-app/public/assets
+    # make router catchall routes
+    sed -i -e 's/auto/hash/' $target/config/environment.js
+
+    # add an image to a template
+    echo '<p>Welcome to Ember</p>' >> $target/app/templates/application.hbs
+    echo '<img src="assets/logo.png">' >> $target/app/templates/application.hbs
+    mkdir -p $target/public/assets
+    cp spec/fixtures/logo.png $target/public/assets
+
+    cd $target &&
+      npm install --save-dev ember-cli-rails-addon@rondale-sc/ember-cli-rails-addon
+      bower install
+  fi
+}
+
+setup_ember
diff --git a/ember-cli-rails.gemspec b/ember-cli-rails.gemspec
index b70040ec..86a8675a 100644
--- a/ember-cli-rails.gemspec
+++ b/ember-cli-rails.gemspec
@@ -13,10 +13,10 @@ Gem::Specification.new do |spec|
   spec.license  = "MIT"
   spec.files    = Dir["README.md", "CHANGELOG.md", "LICENSE.txt", "{lib,app,config}/**/*"]
 
-  spec.required_ruby_version = ">= 2.1.0"
+  spec.required_ruby_version = ">= 2.2.0"
 
   spec.add_dependency "ember-cli-rails-assets", "~> 0.6.2"
-  spec.add_dependency "railties", ">= 3.2", "< 5"
+  spec.add_dependency "railties", ">= 3.2"
   spec.add_dependency "cocaine", "~> 0.5.8"
   spec.add_dependency "html_page", "~> 0.1.0"
 end
diff --git a/gemfiles/3.2.gemfile b/gemfiles/3.2.gemfile
new file mode 100644
index 00000000..335c1f69
--- /dev/null
+++ b/gemfiles/3.2.gemfile
@@ -0,0 +1,19 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "appraisal"
+gem "rails", :git => "https://github.com/rails/rails.git", :branch => "3-2-stable"
+gem "pry"
+
+group :development, :test do
+  gem "high_voltage", "~> 3.0.0"
+  gem "rspec-rails", "~> 3.5.0"
+end
+
+group :test do
+  gem "poltergeist", "~> 1.8.0"
+  gem "codeclimate-test-reporter", :require => nil
+end
+
+gemspec :path => "../"
diff --git a/gemfiles/4.1.gemfile b/gemfiles/4.1.gemfile
index e03a704e..4509e1e5 100644
--- a/gemfiles/4.1.gemfile
+++ b/gemfiles/4.1.gemfile
@@ -7,8 +7,8 @@ gem "rails", "~> 4.1.1"
 gem "pry"
 
 group :development, :test do
-  gem "high_voltage", "~> 2.4.0"
-  gem "rspec-rails", "~> 3.3.0"
+  gem "high_voltage", "~> 3.0.0"
+  gem "rspec-rails", "~> 3.5.0"
 end
 
 group :test do
diff --git a/gemfiles/4.2.gemfile b/gemfiles/4.2.gemfile
index bf8203eb..4900e2db 100644
--- a/gemfiles/4.2.gemfile
+++ b/gemfiles/4.2.gemfile
@@ -7,8 +7,8 @@ gem "rails", "~> 4.2.1"
 gem "pry"
 
 group :development, :test do
-  gem "high_voltage", "~> 2.4.0"
-  gem "rspec-rails", "~> 3.3.0"
+  gem "high_voltage", "~> 3.0.0"
+  gem "rspec-rails", "~> 3.5.0"
 end
 
 group :test do
diff --git a/gemfiles/5.0.0.gemfile b/gemfiles/5.0.0.gemfile
new file mode 100644
index 00000000..1382dfb1
--- /dev/null
+++ b/gemfiles/5.0.0.gemfile
@@ -0,0 +1,19 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "appraisal"
+gem "rails", "5.0.0"
+gem "pry"
+
+group :development, :test do
+  gem "high_voltage", "~> 3.0.0"
+  gem "rspec-rails", "~> 3.5.0"
+end
+
+group :test do
+  gem "poltergeist", "~> 1.8.0"
+  gem "codeclimate-test-reporter", :require => nil
+end
+
+gemspec :path => "../"
diff --git a/gemfiles/master.gemfile b/gemfiles/master.gemfile
new file mode 100644
index 00000000..1216246d
--- /dev/null
+++ b/gemfiles/master.gemfile
@@ -0,0 +1,19 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "appraisal"
+gem "rails", :git => "https://github.com/rails/rails.git", :branch => "master"
+gem "pry"
+
+group :development, :test do
+  gem "high_voltage", "~> 3.0.0"
+  gem "rspec-rails", "~> 3.5.0"
+end
+
+group :test do
+  gem "poltergeist", "~> 1.8.0"
+  gem "codeclimate-test-reporter", :require => nil
+end
+
+gemspec :path => "../"
diff --git a/spec/lib/ember_cli/app_spec.rb b/spec/lib/ember_cli/app_spec.rb
index a0d7479d..909fd6e0 100644
--- a/spec/lib/ember_cli/app_spec.rb
+++ b/spec/lib/ember_cli/app_spec.rb
@@ -27,7 +27,7 @@
 
   describe "#compile" do
     it "exits with exit status of 0" do
-      passed = silence_stdout { EmberCli["my-app"].compile }
+      passed = EmberCli["my-app"].compile
 
       expect(passed).to be true
     end
@@ -35,7 +35,7 @@
 
   describe "#test" do
     it "exits with exit status of 0" do
-      passed = silence_stdout { EmberCli["my-app"].test }
+      passed = EmberCli["my-app"].test
 
       expect(passed).to be true
     end
@@ -65,12 +65,6 @@
     end
   end
 
-  def silence_stdout
-    silence_stream($stdout) do
-      yield
-    end
-  end
-
   def stub_paths(method_to_value)
     allow_any_instance_of(EmberCli::PathSet).
       to receive(method_to_value.keys.first).