diff --git a/.github/workflows/rubocop.yml b/.github/workflows/rubocop.yml
index c3962d1..3e2919a 100644
--- a/.github/workflows/rubocop.yml
+++ b/.github/workflows/rubocop.yml
@@ -8,6 +8,6 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "3.1.2"
+          ruby-version: 3.3.3
           bundler-cache: true
       - run: bundle exec rubocop
diff --git a/.rubocop.yml b/.rubocop.yml
index 440c672..ed78494 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -16,6 +16,7 @@ Layout/LineLength:
 require:
   - rubocop-capybara
   - rubocop-rails
+  - rubocop-rspec_rails
   - rubocop-rake
   - rubocop-rspec
 
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index a2a2ca7..8d244e1 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2024-03-19 16:06:55 UTC using RuboCop version 1.62.1.
+# on 2024-08-31 12:33:26 UTC using RuboCop version 1.62.1.
 # 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
@@ -14,6 +14,7 @@ Lint/EmptyBlock:
 
 # Offense count: 1
 # This cop supports unsafe autocorrection (--autocorrect-all).
+# Configuration parameters: AutoCorrect.
 RSpec/EmptyExampleGroup:
   Exclude:
     - 'spec/helpers/welcome_helper_spec.rb'
@@ -21,12 +22,21 @@ RSpec/EmptyExampleGroup:
 # Offense count: 4
 # Configuration parameters: CountAsOne.
 RSpec/ExampleLength:
-  Max: 13
+  Max: 22
 
 # Offense count: 5
-# Configuration parameters: Include, CustomTransform, IgnoreMethods, SpecSuffixOnly.
-# Include: **/*_spec*rb*, **/spec/**/*
-RSpec/FilePath:
+RSpec/MultipleExpectations:
+  Max: 2
+
+# Offense count: 2
+RSpec/RepeatedExample:
+  Exclude:
+    - 'spec/api/headers_spec.rb'
+
+# Offense count: 5
+# Configuration parameters: Include, CustomTransform, IgnoreMethods, IgnoreMetadata.
+# Include: **/*_spec.rb
+RSpec/SpecFilePathFormat:
   Exclude:
     - 'spec/api/headers_spec.rb'
     - 'spec/api/ping_spec.rb'
@@ -34,15 +44,11 @@ RSpec/FilePath:
     - 'spec/api/protected_spec.rb'
     - 'spec/api/raise_spec.rb'
 
-# Offense count: 4
-RSpec/MultipleExpectations:
-  Max: 2
-
 # Offense count: 4
 # This cop supports unsafe autocorrection (--autocorrect-all).
 # Configuration parameters: ResponseMethods.
 # ResponseMethods: response, last_response
-RSpec/Rails/HaveHttpStatus:
+RSpecRails/HaveHttpStatus:
   Exclude:
     - 'spec/api/post_spec.rb'
     - 'spec/api/protected_spec.rb'
@@ -50,23 +56,7 @@ RSpec/Rails/HaveHttpStatus:
 # Offense count: 2
 # This cop supports unsafe autocorrection (--autocorrect-all).
 # Configuration parameters: Inferences.
-RSpec/Rails/InferredSpecType:
+RSpecRails/InferredSpecType:
   Exclude:
     - 'spec/features/homepage_spec.rb'
     - 'spec/features/swagger_spec.rb'
-
-# Offense count: 2
-RSpec/RepeatedExample:
-  Exclude:
-    - 'spec/api/headers_spec.rb'
-
-# Offense count: 5
-# Configuration parameters: Include, CustomTransform, IgnoreMethods, IgnoreMetadata.
-# Include: **/*_spec.rb
-RSpec/SpecFilePathFormat:
-  Exclude:
-    - 'spec/api/headers_spec.rb'
-    - 'spec/api/ping_spec.rb'
-    - 'spec/api/post_spec.rb'
-    - 'spec/api/protected_spec.rb'
-    - 'spec/api/raise_spec.rb'
diff --git a/Gemfile b/Gemfile
index 71679fe..f200066 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem 'sprockets-rails'
 gem 'pg', '~> 1.1'
 
 # Use the Puma web server [/~https://github.com/puma/puma]
-gem 'puma', '~> 5.6'
+gem 'puma'
 
 # Use JavaScript with ESM import maps [/~https://github.com/rails/importmap-rails]
 gem 'importmap-rails'
@@ -46,7 +46,7 @@ gem 'bootsnap', require: false
 # Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
 # gem "image_processing", "~> 1.2"
 
-gem 'grape', '~> 1.7'
+gem 'grape', '~> 2.1'
 gem 'grape-swagger'
 
 group :development, :test do
@@ -77,6 +77,6 @@ group :test do
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
+  gem 'rubocop-rspec_rails'
   gem 'selenium-webdriver'
-  gem 'webdrivers'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 53bd72b..32524ff 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -66,73 +66,78 @@ GEM
       i18n (>= 1.6, < 2)
       minitest (>= 5.1)
       tzinfo (~> 2.0)
-    addressable (2.8.0)
-      public_suffix (>= 2.0.2, < 5.0)
-    appraisal (2.4.1)
+    addressable (2.8.7)
+      public_suffix (>= 2.0.2, < 7.0)
+    appraisal (2.5.0)
       bundler
       rake
       thor (>= 0.14.0)
     ast (2.4.2)
+    base64 (0.2.0)
+    bigdecimal (3.1.8)
     bindex (0.8.1)
-    bootsnap (1.12.0)
+    bootsnap (1.18.4)
       msgpack (~> 1.2)
-    builder (3.2.4)
-    capybara (3.37.1)
+    builder (3.3.0)
+    capybara (3.40.0)
       addressable
       matrix
       mini_mime (>= 0.1.3)
-      nokogiri (~> 1.8)
+      nokogiri (~> 1.11)
       rack (>= 1.6.0)
       rack-test (>= 0.6.3)
       regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
-    childprocess (4.1.0)
-    concurrent-ruby (1.3.1)
+    concurrent-ruby (1.3.4)
     crass (1.0.6)
     date (3.3.4)
-    debug (1.5.0)
-      irb (>= 1.3.6)
-      reline (>= 0.2.7)
-    diff-lcs (1.5.0)
-    dry-core (1.0.0)
+    debug (1.9.2)
+      irb (~> 1.10)
+      reline (>= 0.3.8)
+    diff-lcs (1.5.1)
+    dry-core (1.0.1)
       concurrent-ruby (~> 1.0)
       zeitwerk (~> 2.6)
-    dry-inflector (1.0.0)
+    dry-inflector (1.1.0)
     dry-logic (1.5.0)
       concurrent-ruby (~> 1.0)
       dry-core (~> 1.0, < 2)
       zeitwerk (~> 2.6)
-    dry-types (1.7.1)
+    dry-types (1.7.2)
+      bigdecimal (~> 3.0)
       concurrent-ruby (~> 1.0)
       dry-core (~> 1.0)
       dry-inflector (~> 1.0)
       dry-logic (~> 1.4)
       zeitwerk (~> 2.6)
-    erubi (1.12.0)
+    erubi (1.13.0)
     globalid (1.2.1)
       activesupport (>= 6.1)
-    grape (1.7.0)
-      activesupport
-      builder
+    grape (2.1.3)
+      activesupport (>= 6)
       dry-types (>= 1.1)
-      mustermann-grape (~> 1.0.0)
-      rack (>= 1.3.0)
-      rack-accept
-    grape-swagger (1.6.0)
-      grape (~> 1.3)
+      mustermann-grape (~> 1.1.0)
+      rack (>= 2)
+      zeitwerk
+    grape-swagger (2.1.0)
+      grape (>= 1.7, < 3.0)
+      rack-test (~> 2)
     i18n (1.14.5)
       concurrent-ruby (~> 1.0)
-    importmap-rails (1.1.1)
+    importmap-rails (2.0.1)
       actionpack (>= 6.0.0)
+      activesupport (>= 6.0.0)
       railties (>= 6.0.0)
-    io-console (0.5.11)
-    irb (1.4.1)
-      reline (>= 0.3.0)
-    jbuilder (2.11.5)
+    io-console (0.7.2)
+    irb (1.14.0)
+      rdoc (>= 4.0.0)
+      reline (>= 0.4.2)
+    jbuilder (2.12.0)
       actionview (>= 5.0.0)
       activesupport (>= 5.0.0)
-    json (2.7.1)
+    json (2.7.2)
     language_server-protocol (3.17.0.3)
+    logger (1.6.0)
     loofah (2.22.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
@@ -143,42 +148,48 @@ GEM
       net-smtp
     marcel (1.0.4)
     matrix (0.4.2)
-    method_source (1.0.0)
+    method_source (1.1.0)
     mini_mime (1.1.5)
-    minitest (5.23.1)
-    msgpack (1.5.2)
-    mustermann (3.0.0)
+    minitest (5.25.1)
+    msgpack (1.7.2)
+    mustermann (3.0.2)
       ruby2_keywords (~> 0.0.1)
-    mustermann-grape (1.0.2)
+    mustermann-grape (1.1.0)
       mustermann (>= 1.0.0)
-    net-imap (0.4.10)
+    net-imap (0.4.15)
       date
       net-protocol
     net-pop (0.1.2)
       net-protocol
     net-protocol (0.2.2)
       timeout
-    net-smtp (0.4.0.1)
+    net-smtp (0.5.0)
       net-protocol
-    nio4r (2.7.0)
-    nokogiri (1.16.5-arm64-darwin)
+    nio4r (2.7.3)
+    nokogiri (1.16.7-aarch64-linux)
+      racc (~> 1.4)
+    nokogiri (1.16.7-arm-linux)
+      racc (~> 1.4)
+    nokogiri (1.16.7-arm64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.16.7-x86-linux)
       racc (~> 1.4)
-    nokogiri (1.16.5-x86_64-darwin)
+    nokogiri (1.16.7-x86_64-darwin)
       racc (~> 1.4)
-    nokogiri (1.16.5-x86_64-linux)
+    nokogiri (1.16.7-x86_64-linux)
       racc (~> 1.4)
-    parallel (1.24.0)
-    parser (3.3.0.5)
+    parallel (1.26.3)
+    parser (3.3.4.2)
       ast (~> 2.4.1)
       racc
-    pg (1.3.5)
-    public_suffix (4.0.7)
-    puma (5.6.8)
+    pg (1.5.7)
+    psych (5.1.2)
+      stringio
+    public_suffix (6.0.1)
+    puma (6.4.2)
       nio4r (~> 2.0)
-    racc (1.8.0)
+    racc (1.8.1)
     rack (2.2.9)
-    rack-accept (0.4.5)
-      rack (>= 0.4)
     rack-test (2.1.0)
       rack (>= 1.3)
     rails (7.0.8.4)
@@ -210,32 +221,35 @@ GEM
       thor (~> 1.0)
       zeitwerk (~> 2.5)
     rainbow (3.1.1)
-    rake (13.1.0)
-    regexp_parser (2.5.0)
-    reline (0.3.1)
+    rake (13.2.1)
+    rdoc (6.7.0)
+      psych (>= 4.0.0)
+    regexp_parser (2.9.2)
+    reline (0.5.9)
       io-console (~> 0.5)
-    rexml (3.2.5)
-    rspec (3.11.0)
-      rspec-core (~> 3.11.0)
-      rspec-expectations (~> 3.11.0)
-      rspec-mocks (~> 3.11.0)
-    rspec-core (3.11.0)
-      rspec-support (~> 3.11.0)
-    rspec-expectations (3.11.0)
+    rexml (3.3.6)
+      strscan
+    rspec (3.13.0)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.0)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.2)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.11.0)
-    rspec-mocks (3.11.1)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.1)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.11.0)
-    rspec-rails (5.1.2)
-      actionpack (>= 5.2)
-      activesupport (>= 5.2)
-      railties (>= 5.2)
-      rspec-core (~> 3.10)
-      rspec-expectations (~> 3.10)
-      rspec-mocks (~> 3.10)
-      rspec-support (~> 3.10)
-    rspec-support (3.11.0)
+      rspec-support (~> 3.13.0)
+    rspec-rails (6.1.4)
+      actionpack (>= 6.1)
+      activesupport (>= 6.1)
+      railties (>= 6.1)
+      rspec-core (~> 3.13)
+      rspec-expectations (~> 3.13)
+      rspec-mocks (~> 3.13)
+      rspec-support (~> 3.13)
+    rspec-support (3.13.1)
     rubocop (1.62.1)
       json (~> 2.3)
       language_server-protocol (>= 3.17.0)
@@ -247,70 +261,70 @@ GEM
       rubocop-ast (>= 1.31.1, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.31.2)
-      parser (>= 3.3.0.4)
-    rubocop-capybara (2.20.0)
-      rubocop (~> 1.41)
-    rubocop-factory_bot (2.25.1)
+    rubocop-ast (1.32.1)
+      parser (>= 3.3.1.0)
+    rubocop-capybara (2.21.0)
       rubocop (~> 1.41)
-    rubocop-rails (2.24.0)
+    rubocop-rails (2.26.0)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
-      rubocop (>= 1.33.0, < 2.0)
+      rubocop (>= 1.52.0, < 2.0)
       rubocop-ast (>= 1.31.1, < 2.0)
     rubocop-rake (0.6.0)
       rubocop (~> 1.0)
-    rubocop-rspec (2.27.1)
-      rubocop (~> 1.40)
-      rubocop-capybara (~> 2.17)
-      rubocop-factory_bot (~> 2.22)
+    rubocop-rspec (3.0.4)
+      rubocop (~> 1.61)
+    rubocop-rspec_rails (2.30.0)
+      rubocop (~> 1.61)
+      rubocop-rspec (~> 3, >= 3.0.1)
     ruby-progressbar (1.13.0)
     ruby2_keywords (0.0.5)
     rubyzip (2.3.2)
-    selenium-webdriver (4.2.1)
-      childprocess (>= 0.5, < 5.0)
+    selenium-webdriver (4.24.0)
+      base64 (~> 0.2)
+      logger (~> 1.4)
       rexml (~> 3.2, >= 3.2.5)
       rubyzip (>= 1.2.2, < 3.0)
       websocket (~> 1.0)
-    sprockets (4.0.3)
+    sprockets (4.2.1)
       concurrent-ruby (~> 1.0)
-      rack (> 1, < 3)
-    sprockets-rails (3.4.2)
-      actionpack (>= 5.2)
-      activesupport (>= 5.2)
+      rack (>= 2.2.4, < 4)
+    sprockets-rails (3.5.2)
+      actionpack (>= 6.1)
+      activesupport (>= 6.1)
       sprockets (>= 3.0.0)
-    stimulus-rails (1.0.4)
+    stimulus-rails (1.3.4)
       railties (>= 6.0.0)
-    thor (1.3.1)
+    stringio (3.1.1)
+    strscan (3.1.0)
+    thor (1.3.2)
     timeout (0.4.1)
-    turbo-rails (1.1.1)
+    turbo-rails (2.0.6)
       actionpack (>= 6.0.0)
       activejob (>= 6.0.0)
       railties (>= 6.0.0)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
     unicode-display_width (2.5.0)
-    web-console (4.2.0)
+    web-console (4.2.1)
       actionview (>= 6.0.0)
       activemodel (>= 6.0.0)
       bindex (>= 0.4.0)
       railties (>= 6.0.0)
-    webdrivers (5.0.0)
-      nokogiri (~> 1.6)
-      rubyzip (>= 1.3.0)
-      selenium-webdriver (~> 4.0)
-    websocket (1.2.9)
+    websocket (1.2.11)
     websocket-driver (0.7.6)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
-    zeitwerk (2.6.13)
+    zeitwerk (2.6.17)
 
 PLATFORMS
-  arm64-darwin-21
-  x86_64-darwin-19
-  x86_64-darwin-20
+  aarch64-linux
+  arm-linux
+  arm64-darwin
+  x86-linux
+  x86_64-darwin
   x86_64-linux
 
 DEPENDENCIES
@@ -318,12 +332,12 @@ DEPENDENCIES
   bootsnap
   capybara
   debug
-  grape (~> 1.7)
+  grape (~> 2.1)
   grape-swagger
   importmap-rails
   jbuilder
   pg (~> 1.1)
-  puma (~> 5.6)
+  puma
   rails (~> 7.0.8)
   rspec
   rspec-rails
@@ -332,13 +346,13 @@ DEPENDENCIES
   rubocop-rails
   rubocop-rake
   rubocop-rspec
+  rubocop-rspec_rails
   selenium-webdriver
   sprockets-rails
   stimulus-rails
   turbo-rails
   tzinfo-data
   web-console
-  webdrivers
 
 BUNDLED WITH
-   2.3.26
+   2.5.2
diff --git a/gemfiles/rails_6.gemfile b/gemfiles/rails_6.gemfile
index 4bf9ccf..596af58 100644
--- a/gemfiles/rails_6.gemfile
+++ b/gemfiles/rails_6.gemfile
@@ -3,12 +3,12 @@
 source 'https://rubygems.org'
 
 gem 'bootsnap', require: false
-gem 'grape', '~> 1.7'
+gem 'grape', '~> 2.1'
 gem 'grape-swagger'
 gem 'importmap-rails'
 gem 'jbuilder'
 gem 'pg', '~> 1.1'
-gem 'puma', '~> 5.6'
+gem 'puma'
 gem 'rails', '~> 6.0'
 gem 'sprockets-rails'
 gem 'stimulus-rails'
@@ -33,6 +33,6 @@ group :test do
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
+  gem 'rubocop-rspec_rails'
   gem 'selenium-webdriver'
-  gem 'webdrivers'
 end
diff --git a/gemfiles/rails_6_1.gemfile b/gemfiles/rails_6_1.gemfile
index 412d942..0ee3efa 100644
--- a/gemfiles/rails_6_1.gemfile
+++ b/gemfiles/rails_6_1.gemfile
@@ -3,12 +3,12 @@
 source 'https://rubygems.org'
 
 gem 'bootsnap', require: false
-gem 'grape', '~> 1.7'
+gem 'grape', '~> 2.1'
 gem 'grape-swagger'
 gem 'importmap-rails'
 gem 'jbuilder'
 gem 'pg', '~> 1.1'
-gem 'puma', '~> 5.6'
+gem 'puma'
 gem 'rails', '~> 6.1'
 gem 'sprockets-rails'
 gem 'stimulus-rails'
@@ -33,6 +33,6 @@ group :test do
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
+  gem 'rubocop-rspec_rails'
   gem 'selenium-webdriver'
-  gem 'webdrivers'
 end
diff --git a/gemfiles/rails_7.gemfile b/gemfiles/rails_7.gemfile
index 2e980a5..a15c028 100644
--- a/gemfiles/rails_7.gemfile
+++ b/gemfiles/rails_7.gemfile
@@ -3,12 +3,12 @@
 source 'https://rubygems.org'
 
 gem 'bootsnap', require: false
-gem 'grape', '~> 1.7'
+gem 'grape', '~> 2.1'
 gem 'grape-swagger'
 gem 'importmap-rails'
 gem 'jbuilder'
 gem 'pg', '~> 1.1'
-gem 'puma', '~> 6.4.2'
+gem 'puma'
 gem 'rails', '~> 7.0'
 gem 'sprockets-rails'
 gem 'stimulus-rails'
@@ -33,6 +33,6 @@ group :test do
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
+  gem 'rubocop-rspec_rails'
   gem 'selenium-webdriver'
-  gem 'webdrivers'
 end
diff --git a/gemfiles/rails_edge.gemfile b/gemfiles/rails_edge.gemfile
index 49440a0..6ae245c 100644
--- a/gemfiles/rails_edge.gemfile
+++ b/gemfiles/rails_edge.gemfile
@@ -3,12 +3,12 @@
 source 'https://rubygems.org'
 
 gem 'bootsnap', require: false
-gem 'grape', '~> 1.7'
+gem 'grape', '~> 2.1'
 gem 'grape-swagger'
 gem 'importmap-rails'
 gem 'jbuilder'
 gem 'pg', '~> 1.1'
-gem 'puma', '~> 6.4.2'
+gem 'puma'
 gem 'rails', git: '/~https://github.com/rails/rails.git'
 gem 'sprockets-rails'
 gem 'stimulus-rails'
@@ -33,6 +33,6 @@ group :test do
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
+  gem 'rubocop-rspec_rails'
   gem 'selenium-webdriver'
-  gem 'webdrivers'
 end
diff --git a/spec/api/headers_spec.rb b/spec/api/headers_spec.rb
index ff860a7..5705a61 100644
--- a/spec/api/headers_spec.rb
+++ b/spec/api/headers_spec.rb
@@ -3,11 +3,19 @@
 describe Acme::Headers do
   it 'returns all headers' do
     get '/api/headers'
-    expect(JSON.parse(response.body)).to include(
-      'Accept' => 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5',
-      'Cookie' => '',
-      'Host' => 'www.example.com'
-    )
+    if Gem::Version.new(Rack.release) >= Gem::Version.new('3')
+      expect(JSON.parse(response.body)).to include(
+        'accept' => 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5',
+        'cookie' => '',
+        'host' => 'www.example.com'
+      )
+    else
+      expect(JSON.parse(response.body)).to include(
+        'Accept' => 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5',
+        'Cookie' => '',
+        'Host' => 'www.example.com'
+      )
+    end
   end
 
   it 'returns a Host header' do
@@ -20,18 +28,29 @@
     expect(JSON.parse(response.body)).to eq('Host' => 'www.example.com')
   end
 
-  it 'headers via arg' do
+  it "headers via arg (rack #{Rack.release})" do
     get '/api/headers', headers: {
       'HTTP_RETICULATED_SPLINE' => 42,
       'Something' => 1,
       'SOMETHING_ELSE' => 1
     }
-    expect(JSON.parse(response.body)).to include(
-      'Accept' => 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5',
-      'Cookie' => '',
-      'Host' => 'www.example.com',
-      'Reticulated-Spline' => 42,
-      'Something' => 1
-    )
+
+    if Gem::Version.new(Rack.release) >= Gem::Version.new('3')
+      expect(JSON.parse(response.body)).to include(
+        'accept' => 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5',
+        'cookie' => '',
+        'host' => 'www.example.com',
+        'reticulated-spline' => 42,
+        'something' => 1
+      )
+    else
+      expect(JSON.parse(response.body)).to include(
+        'Accept' => 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5',
+        'Cookie' => '',
+        'Host' => 'www.example.com',
+        'reticulated-spline' => 42,
+        'something' => 1
+      )
+    end
   end
 end