diff --git a/.rubocop.yml b/.rubocop.yml
index 4131cc4..af032d6 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -17,3 +17,9 @@ Style/FrozenStringLiteralComment:
   Enabled: false
 
 inherit_from: .rubocop_todo.yml
+
+require:
+  - rubocop-capybara
+  - rubocop-rake
+  - rubocop-rspec
+
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index e6dbdcf..ffa2449 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,15 +1,110 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2022-06-18 16:28:15 UTC using RuboCop version 1.30.1.
+# on 2023-11-08 18:43:53 UTC using RuboCop version 1.57.2.
 # 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.
 
 # Offense count: 1
-Lint/UriEscapeUnescape:
+# This cop supports unsafe autocorrection (--autocorrect-all).
+RSpec/BeEql:
   Exclude:
-    - 'api/upload_file.rb'
+    - 'spec/api/documentation_spec.rb'
+
+# Offense count: 14
+# Configuration parameters: Prefixes, AllowedPatterns.
+# Prefixes: when, with, without
+RSpec/ContextWording:
+  Exclude:
+    - 'spec/api/content_type_spec.rb'
+    - 'spec/api/cors_spec.rb'
+    - 'spec/api/documentation_spec.rb'
+    - 'spec/api/header_versioning_spec.rb'
+    - 'spec/api/post_put_spec.rb'
+    - 'spec/integration/grape_on_rack_spec.rb'
+
+# Offense count: 1
+# This cop supports unsafe autocorrection (--autocorrect-all).
+RSpec/EmptyExampleGroup:
+  Exclude:
+    - 'spec/api/documentation_spec.rb'
+
+# Offense count: 12
+# Configuration parameters: CountAsOne.
+RSpec/ExampleLength:
+  Max: 11
+
+# Offense count: 3
+RSpec/ExpectInHook:
+  Exclude:
+    - 'spec/api/documentation_spec.rb'
+
+# Offense count: 15
+# Configuration parameters: Include, CustomTransform, IgnoreMethods, SpecSuffixOnly.
+# Include: **/*_spec*rb*, **/spec/**/*
+RSpec/FilePath:
+  Exclude:
+    - 'spec/api/content_type_spec.rb'
+    - 'spec/api/cors_spec.rb'
+    - 'spec/api/documentation_spec.rb'
+    - 'spec/api/entities_spec.rb'
+    - 'spec/api/get_json_spec.rb'
+    - 'spec/api/header_versioning_spec.rb'
+    - 'spec/api/headers_spec.rb'
+    - 'spec/api/path_versioning_spec.rb'
+    - 'spec/api/ping_spec.rb'
+    - 'spec/api/post_json_spec.rb'
+    - 'spec/api/post_put_spec.rb'
+    - 'spec/api/rescue_from_spec.rb'
+    - 'spec/api/stream_data_spec.rb'
+    - 'spec/api/upload_file_spec.rb'
+    - 'spec/api/wrap_response_spec.rb'
+
+# Offense count: 9
+# Configuration parameters: AssignmentOnly.
+RSpec/InstanceVariable:
+  Exclude:
+    - 'spec/api/documentation_spec.rb'
+    - 'spec/api/post_put_spec.rb'
+    - 'spec/integration/grape_on_rack_spec.rb'
+
+# Offense count: 26
+RSpec/MultipleExpectations:
+  Max: 4
+
+# Offense count: 2
+RSpec/RepeatedExample:
+  Exclude:
+    - 'spec/api/headers_spec.rb'
+
+# Offense count: 15
+# Configuration parameters: Include, CustomTransform, IgnoreMethods, IgnoreMetadata.
+# Include: **/*_spec.rb
+RSpec/SpecFilePathFormat:
+  Exclude:
+    - '**/spec/routing/**/*'
+    - 'spec/api/content_type_spec.rb'
+    - 'spec/api/cors_spec.rb'
+    - 'spec/api/documentation_spec.rb'
+    - 'spec/api/entities_spec.rb'
+    - 'spec/api/get_json_spec.rb'
+    - 'spec/api/header_versioning_spec.rb'
+    - 'spec/api/headers_spec.rb'
+    - 'spec/api/path_versioning_spec.rb'
+    - 'spec/api/ping_spec.rb'
+    - 'spec/api/post_json_spec.rb'
+    - 'spec/api/post_put_spec.rb'
+    - 'spec/api/rescue_from_spec.rb'
+    - 'spec/api/stream_data_spec.rb'
+    - 'spec/api/upload_file_spec.rb'
+    - 'spec/api/wrap_response_spec.rb'
+
+# Offense count: 2
+# This cop supports safe autocorrection (--autocorrect).
+Rake/Desc:
+  Exclude:
+    - 'Rakefile'
 
 # Offense count: 1
 # This cop supports safe autocorrection (--autocorrect).
@@ -35,3 +130,10 @@ Style/OpenStructUse:
 Style/RescueModifier:
   Exclude:
     - 'api/get_json.rb'
+
+# Offense count: 1
+# This cop supports unsafe autocorrection (--autocorrect-all).
+# Configuration parameters: Mode.
+Style/StringConcatenation:
+  Exclude:
+    - 'api/stream_data.rb'
diff --git a/Gemfile b/Gemfile
index 0144f34..e64f49c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,9 +8,10 @@ gem 'json'
 gem 'mime-types'
 gem 'newrelic_rpm'
 gem 'nokogiri'
-gem 'rack', '< 3'
+gem 'puma'
+gem 'rack'
 gem 'rack-cors'
-gem 'webrick'
+gem 'rackup'
 
 group :development do
   gem 'guard'
@@ -18,6 +19,7 @@ group :development do
   gem 'guard-rack'
   gem 'rake'
   gem 'rubocop'
+  gem 'rubocop-capybara'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index ea9aba9..086db23 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,16 +1,23 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    activesupport (7.0.7.2)
+    activesupport (7.1.1)
+      base64
+      bigdecimal
       concurrent-ruby (~> 1.0, >= 1.0.2)
+      connection_pool (>= 2.2.5)
+      drb
       i18n (>= 1.6, < 2)
       minitest (>= 5.1)
+      mutex_m
       tzinfo (~> 2.0)
-    addressable (2.8.1)
+    addressable (2.8.5)
       public_suffix (>= 2.0.2, < 6.0)
     ast (2.4.2)
+    base64 (0.2.0)
+    bigdecimal (3.1.4)
     builder (3.2.4)
-    capybara (3.38.0)
+    capybara (3.39.2)
       addressable
       matrix
       mini_mime (>= 0.1.3)
@@ -21,7 +28,10 @@ GEM
       xpath (~> 3.2)
     coderay (1.1.3)
     concurrent-ruby (1.2.2)
+    connection_pool (2.4.1)
     diff-lcs (1.5.0)
+    drb (2.2.0)
+      ruby2_keywords
     dry-core (1.0.0)
       concurrent-ruby (~> 1.0)
       zeitwerk (~> 2.6)
@@ -36,10 +46,10 @@ GEM
       dry-inflector (~> 1.0)
       dry-logic (~> 1.4)
       zeitwerk (~> 2.6)
-    ffi (1.15.5)
+    ffi (1.16.3)
     formatador (1.1.0)
-    grape (1.7.0)
-      activesupport
+    grape (1.8.0)
+      activesupport (>= 5)
       builder
       dry-types (>= 1.1)
       mustermann-grape (~> 1.0.0)
@@ -48,12 +58,12 @@ GEM
     grape-entity (1.0.0)
       activesupport (>= 3.0.0)
       multi_json (>= 1.3.2)
-    grape-swagger (1.6.0)
+    grape-swagger (1.6.1)
       grape (~> 1.3)
-    grape-swagger-entity (0.5.1)
+    grape-swagger-entity (0.5.2)
       grape-entity (>= 0.6.0)
       grape-swagger (>= 1.2.0)
-    guard (2.18.0)
+    guard (2.18.1)
       formatador (>= 0.2.4)
       listen (>= 2.7, < 4.0)
       lumberjack (>= 1.0.12, < 2.0)
@@ -74,104 +84,118 @@ GEM
     i18n (1.14.1)
       concurrent-ruby (~> 1.0)
     json (2.6.3)
+    language_server-protocol (3.17.0.3)
     listen (3.8.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
-    lumberjack (1.2.8)
+    lumberjack (1.2.9)
     matrix (0.4.2)
     method_source (1.0.0)
-    mime-types (3.4.1)
+    mime-types (3.5.1)
       mime-types-data (~> 3.2015)
-    mime-types-data (3.2023.0218.1)
-    mini_mime (1.1.2)
-    mini_portile2 (2.8.1)
-    minitest (5.19.0)
+    mime-types-data (3.2023.1003)
+    mini_mime (1.1.5)
+    mini_portile2 (2.8.5)
+    minitest (5.20.0)
     multi_json (1.15.0)
     mustermann (3.0.0)
       ruby2_keywords (~> 0.0.1)
     mustermann-grape (1.0.2)
       mustermann (>= 1.0.0)
+    mutex_m (0.2.0)
     nenv (0.3.0)
-    newrelic_rpm (9.0.0)
-    nokogiri (1.14.3)
-      mini_portile2 (~> 2.8.0)
+    newrelic_rpm (9.6.0)
+      base64
+    nio4r (2.5.9)
+    nokogiri (1.15.4)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     notiffany (0.1.3)
       nenv (~> 0.1)
       shellany (~> 0.0)
-    parallel (1.22.1)
-    parser (3.2.1.1)
+    parallel (1.23.0)
+    parser (3.2.2.4)
       ast (~> 2.4.1)
+      racc
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
-    public_suffix (5.0.1)
-    racc (1.6.2)
-    rack (2.2.6.4)
+    public_suffix (5.0.3)
+    puma (6.4.0)
+      nio4r (~> 2.0)
+    racc (1.7.3)
+    rack (3.0.8)
     rack-accept (0.4.5)
       rack (>= 0.4)
     rack-cors (2.0.1)
       rack (>= 2.0.0)
     rack-test (2.1.0)
       rack (>= 1.3)
+    rackup (2.1.0)
+      rack (>= 3)
+      webrick (~> 1.8)
     rainbow (3.1.1)
-    rake (13.0.6)
+    rake (13.1.0)
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    regexp_parser (2.7.0)
-    rexml (3.2.5)
+    regexp_parser (2.8.2)
+    rexml (3.2.6)
     rspec (3.12.0)
       rspec-core (~> 3.12.0)
       rspec-expectations (~> 3.12.0)
       rspec-mocks (~> 3.12.0)
-    rspec-core (3.12.1)
+    rspec-core (3.12.2)
       rspec-support (~> 3.12.0)
-    rspec-expectations (3.12.2)
+    rspec-expectations (3.12.3)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.12.0)
-    rspec-mocks (3.12.4)
+    rspec-mocks (3.12.6)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.12.0)
-    rspec-support (3.12.0)
-    rubocop (1.48.1)
+    rspec-support (3.12.1)
+    rubocop (1.57.2)
       json (~> 2.3)
+      language_server-protocol (>= 3.17.0)
       parallel (~> 1.10)
-      parser (>= 3.2.0.0)
+      parser (>= 3.2.2.4)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.8, < 3.0)
       rexml (>= 3.2.5, < 4.0)
-      rubocop-ast (>= 1.26.0, < 2.0)
+      rubocop-ast (>= 1.28.1, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.28.0)
+    rubocop-ast (1.30.0)
       parser (>= 3.2.1.0)
-    rubocop-capybara (2.17.1)
+    rubocop-capybara (2.19.0)
       rubocop (~> 1.41)
+    rubocop-factory_bot (2.24.0)
+      rubocop (~> 1.33)
     rubocop-rake (0.6.0)
       rubocop (~> 1.0)
-    rubocop-rspec (2.19.0)
-      rubocop (~> 1.33)
+    rubocop-rspec (2.25.0)
+      rubocop (~> 1.40)
       rubocop-capybara (~> 2.17)
+      rubocop-factory_bot (~> 2.22)
     ruby-progressbar (1.13.0)
     ruby2_keywords (0.0.5)
     rubyzip (2.3.2)
-    selenium-webdriver (4.8.2)
+    selenium-webdriver (4.9.0)
       rexml (~> 3.2, >= 3.2.5)
       rubyzip (>= 1.2.2, < 3.0)
       websocket (~> 1.0)
     shellany (0.0.1)
     spoon (0.0.6)
       ffi
-    thor (1.2.1)
+    thor (1.3.0)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    unicode-display_width (2.4.2)
+    unicode-display_width (2.5.0)
     webrick (1.8.1)
-    websocket (1.2.9)
+    websocket (1.2.10)
     xpath (3.2.0)
       nokogiri (~> 1.8)
-    zeitwerk (2.6.7)
+    zeitwerk (2.6.12)
 
 PLATFORMS
   ruby
@@ -189,16 +213,18 @@ DEPENDENCIES
   mime-types
   newrelic_rpm
   nokogiri
-  rack (< 3)
+  puma
+  rack
   rack-cors
   rack-test
+  rackup
   rake
   rspec
   rubocop
+  rubocop-capybara
   rubocop-rake
   rubocop-rspec
   selenium-webdriver
-  webrick
 
 BUNDLED WITH
-   2.3.15
+   2.4.2
diff --git a/README.md b/README.md
index b451e43..ba7cbbf 100644
--- a/README.md
+++ b/README.md
@@ -14,9 +14,14 @@ $ bundle install
 $ rackup
 
 Loading NewRelic in developer mode ...
-[2013-06-20 08:57:58] INFO  WEBrick 1.3.1
-[2013-06-20 08:57:58] INFO  ruby 1.9.3 (2013-02-06) [x86_64-darwin11.4.2]
-[2013-06-20 08:57:58] INFO  WEBrick::HTTPServer#start: pid=247 port=9292
+Puma starting in single mode...
+* Puma version: 6.4.0 (ruby 2.7.7-p221) ("The Eagle of Durango")
+*  Min threads: 0
+*  Max threads: 5
+*  Environment: development
+*          PID: 82944
+* Listening on http://127.0.0.1:9292
+* Listening on http://[::1]:9292
 ```
 
 List Routes
@@ -229,6 +234,18 @@ $ curl http://localhost:9292/api/headers/Host
 {"Host":"localhost:9292"}
 ```
 
+### [stream_data](api/stream_data.rb)
+
+An example of streaming data.
+
+```
+curl http://localhost:9292/api/stream --no-buffer
+1
+2
+3
+...
+```
+
 New Relic
 ---------
 
diff --git a/api/stream_data.rb b/api/stream_data.rb
new file mode 100644
index 0000000..6b739b0
--- /dev/null
+++ b/api/stream_data.rb
@@ -0,0 +1,19 @@
+module Acme
+  class SlowStreamer
+    def each
+      (1..5).each do |i|
+        yield (i.to_s + "\n")
+        sleep 0.3
+      end
+    end
+  end
+
+  class StreamData < Grape::API
+    desc 'Streams data.'
+    get :stream do
+      stream SlowStreamer.new
+      content_type 'text/event-stream'
+      status 200
+    end
+  end
+end
diff --git a/app/api.rb b/app/api.rb
index 3378cd2..1658f6a 100644
--- a/app/api.rb
+++ b/app/api.rb
@@ -14,6 +14,7 @@ class API < Grape::API
     mount ::Acme::UploadFile
     mount ::Acme::Entities::API
     mount ::Acme::Headers
+    mount ::Acme::StreamData
     add_swagger_documentation api_version: 'v1'
   end
 end
diff --git a/public/index.html b/public/index.html
index cbc0ce0..4873bcf 100644
--- a/public/index.html
+++ b/public/index.html
@@ -3,6 +3,7 @@
   <title>Rack Powers Web APIs</title>
   <script src="/scripts/jquery-1.7.1.min.js"></script>
   <script src="/scripts/ring.js"></script>
+  <script src="/scripts/stream.js"></script>
 </head>
  <body>
   <h1>Rack Powers Web APIs</h1>
@@ -14,9 +15,10 @@ <h1>Rack Powers Web APIs</h1>
    <li>
     <div>
       <span id='ring_value'>fetching ring value ...</span>
-      <span id='ring_action' style="text-decoration: underline; cursor: pointer" />
+      <span id='ring_action' style="text-decoration: underline; cursor: pointer"></span>
     </div>
    </li>
+   <li><span id='stream_value'>fetching stream data ...</span></li>
   </ul>
  </body>
 </html>
diff --git a/public/scripts/stream.js b/public/scripts/stream.js
new file mode 100644
index 0000000..0d62b6a
--- /dev/null
+++ b/public/scripts/stream.js
@@ -0,0 +1,13 @@
+$(document).ready(function() {
+
+  var stream = function() {
+    var client = new XMLHttpRequest();
+    client.open('get', '/api/stream');
+    client.send();
+    client.onprogress = function() {
+      $('#stream_value').html($('#stream_value').html() + "<br>" + this.responseText);
+    }
+  };
+
+  stream();
+});
diff --git a/spec/api/cors_spec.rb b/spec/api/cors_spec.rb
index fb8ad2b..f543346 100644
--- a/spec/api/cors_spec.rb
+++ b/spec/api/cors_spec.rb
@@ -18,11 +18,13 @@ def app
       expect(last_response.headers['Access-Control-Allow-Origin']).to eq('*')
       expect(last_response.headers['Access-Control-Expose-Headers']).to eq('')
     end
+
     it 'includes Access-Control-Allow-Origin in the response' do
       get '/api/ping', {}, 'HTTP_ORIGIN' => 'http://cors.example.com'
       expect(last_response.status).to eq(200)
       expect(last_response.headers['Access-Control-Allow-Origin']).to eq('*')
     end
+
     it 'includes Access-Control-Allow-Origin in errors' do
       get '/invalid', {}, 'HTTP_ORIGIN' => 'http://cors.example.com'
       expect(last_response.status).to eq(404)
diff --git a/spec/api/header_versioning_spec.rb b/spec/api/header_versioning_spec.rb
index ad89bae..de637b8 100644
--- a/spec/api/header_versioning_spec.rb
+++ b/spec/api/header_versioning_spec.rb
@@ -13,6 +13,7 @@ def app
       expect(last_response.status).to eq(200)
       expect(last_response.body).to eq({ header: 'acme' }.to_json)
     end
+
     it 'invalid version' do
       get '/api', nil, 'HTTP_ACCEPT' => 'application/vnd.acme-v2+json'
       expect(last_response.status).to eq(404)
diff --git a/spec/api/headers_spec.rb b/spec/api/headers_spec.rb
index 83bc80c..6c6fd8f 100644
--- a/spec/api/headers_spec.rb
+++ b/spec/api/headers_spec.rb
@@ -11,8 +11,7 @@ def app
     get '/api/headers'
     expect(JSON.parse(last_response.body)).to eq(
       'Cookie' => '',
-      'Host' => 'example.org',
-      'Version' => 'HTTP/1.0'
+      'Host' => 'example.org'
     )
   end
 
@@ -39,8 +38,7 @@ def app
     expect(JSON.parse(last_response.body)).to eq(
       'Cookie' => '',
       'Host' => 'example.org',
-      'Reticulated-Spline' => 42,
-      'Version' => 'HTTP/1.0'
+      'Reticulated-Spline' => 42
     )
   end
 end
diff --git a/spec/api/post_put_spec.rb b/spec/api/post_put_spec.rb
index 2711446..2062384 100644
--- a/spec/api/post_put_spec.rb
+++ b/spec/api/post_put_spec.rb
@@ -11,11 +11,13 @@ def app
     get '/api/ring'
     expect(JSON.parse(last_response.body)[:rang].to_i).to be >= 0
   end
+
   context 'with rings' do
-    before :each do
+    before do
       get '/api/ring'
       @rang = JSON.parse(last_response.body)['rang'].to_i
     end
+
     it 'POST ring' do
       2.times do |i|
         post '/api/ring'
@@ -25,12 +27,14 @@ def app
       get '/api/ring'
       expect(last_response.body).to eq({ rang: @rang + 2 }.to_json)
     end
+
     context 'PUT ring' do
       it 'succeeds for 2 rings' do
         put '/api/ring?count=2'
         expect(last_response.status).to eq(200)
         expect(last_response.body).to eq({ rang: @rang + 2 }.to_json)
       end
+
       it 'fails with a missing ring' do
         put '/api/ring'
         expect(last_response.status).to eq(400)
diff --git a/spec/api/stream_data_spec.rb b/spec/api/stream_data_spec.rb
new file mode 100644
index 0000000..9c3883f
--- /dev/null
+++ b/spec/api/stream_data_spec.rb
@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+describe Acme::API do
+  include Rack::Test::Methods
+
+  def app
+    Acme::API
+  end
+
+  it 'returns all data' do
+    get '/api/stream'
+    expect(last_response.status).to eq(200)
+    expect(last_response.instance_variable_get(:@body)).to eq(%W[1\n 2\n 3\n 4\n 5\n])
+    expect(last_response.body).to eq("1\n2\n3\n4\n5\n")
+    expect(last_response.content_type).to eq('text/event-stream')
+  end
+end
diff --git a/spec/integration/grape_on_rack_spec.rb b/spec/integration/grape_on_rack_spec.rb
index 80a3c75..51d074f 100644
--- a/spec/integration/grape_on_rack_spec.rb
+++ b/spec/integration/grape_on_rack_spec.rb
@@ -1,48 +1,66 @@
 require 'spec_helper'
 
-describe 'Grape on RACK', js: true, type: :feature do
+describe 'Grape on RACK', :js, type: :feature do
   context 'homepage' do
     it 'displays index.html page' do
       visit '/'
       expect(title).to eq('Rack Powers Web APIs')
     end
+
     context 'ring' do
-      before :each do
+      before do
         @rang = Acme::PostPut.rang
         visit '/'
       end
+
       it 'increments the ring counter' do
-        expect(find('#ring_value')).to have_content "rang #{@rang + 1} time(s)"
-        expect(find('#ring_action')).to have_content 'click here to ring again'
+        expect(find_by_id('ring_value')).to have_content "rang #{@rang + 1} time(s)"
+        expect(find_by_id('ring_action')).to have_content 'click here to ring again'
         3.times do |i|
-          find('#ring_action').click
-          expect(find('#ring_value')).to have_content "rang #{@rang + i + 2} time(s)"
+          find_by_id('ring_action').click
+          expect(find_by_id('ring_value')).to have_content "rang #{@rang + i + 2} time(s)"
         end
       end
     end
+
+    context 'stream' do
+      before do
+        visit '/'
+      end
+
+      it 'fetches stream data incrementally' do
+        expect(find_by_id('stream_value')).to have_content "fetching stream data ...\n1\n1 2\n1 2 3\n1 2 3 4\n1 2 3 4 5"
+      end
+    end
   end
+
   context "page that doesn't exist" do
-    before :each do
+    before do
       visit '/invalid'
     end
+
     it 'displays 404 page' do
       expect(title).to eq('Page Not Found')
     end
   end
+
   context 'Swagger UI' do
     it 'displays Swagger UI' do
       visit '/swagger/index.html'
       expect(title).to eq('Swagger UI')
     end
   end
+
   context 'exception' do
-    before :each do
+    before do
       visit '/api/raise'
     end
+
     it 'displays 500 page' do
       expect(title).to eq('Unexpected Error')
     end
   end
+
   context 'curl' do
     it 'reticulates a spline' do
       visit '/'
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 3ca6bd5..29099b0 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -19,5 +19,5 @@
 Capybara.configure do |config|
   config.app = Acme::App.new
   config.server_port = 9293
-  config.server = :webrick
+  config.server = :puma
 end