diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 9a19fb6..630f5fa 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -4,16 +4,19 @@ on: [push, pull_request]
 
 jobs:
   test:
-    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         ruby_version: ["2.7", "3.0", "3.1", "3.2", "3.3"]
         os: ["ubuntu-latest","windows-latest","macos-latest"]
+        rack_version: ["2", "3"]
+    runs-on: ${{ matrix.os }}
+    env:
+      RACK_VERSION: ${{ matrix.rack_version }}
     steps:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby_version }}
       - run: "bundle install"
-      - run: "bundle exec rake"
+      - run: "bundle exec rake"
\ No newline at end of file
diff --git a/Gemfile b/Gemfile
index e6cea9d..099b114 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,3 +9,6 @@ if ENV['X_PACT_DEVELOPMENT']
   gem "pact-message", path: '../pact-message-ruby'
   gem "pact-support", path: '../pact-support'
 end
+
+gem 'rack-reverse-proxy', git: 'https://github.com/pact-foundation/rack-reverse-proxy.git',
+                          branch: 'feat/rack_2_and_3_compat'
diff --git a/pact-provider-verifier.gemspec b/pact-provider-verifier.gemspec
index 25d6e96..17eba6b 100644
--- a/pact-provider-verifier.gemspec
+++ b/pact-provider-verifier.gemspec
@@ -26,7 +26,13 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency 'faraday', '~> 2.5'
   gem.add_runtime_dependency 'faraday-retry', '~> 2.2'
   gem.add_runtime_dependency 'json',  '>1.8'
-  gem.add_runtime_dependency 'rack', '~> 2.1'
+  if ENV['RACK_VERSION'] == '2'
+    gem.add_runtime_dependency 'rack', '>= 2.0', '< 3.0'
+  else
+    gem.add_runtime_dependency 'rack', '>= 3.0', '< 4.0'
+    gem.add_runtime_dependency 'rackup', '~> 2.0'
+  end
+  
   gem.add_runtime_dependency 'rack-reverse-proxy'
   gem.add_runtime_dependency 'rspec_junit_formatter', '~> 0.3'
   gem.add_runtime_dependency 'ostruct'
diff --git a/spec/integration_with_pact_broker_config_spec.rb b/spec/integration_with_pact_broker_config_spec.rb
index 6fe7f44..1f74522 100644
--- a/spec/integration_with_pact_broker_config_spec.rb
+++ b/spec/integration_with_pact_broker_config_spec.rb
@@ -1,6 +1,7 @@
 require 'pact/provider_verifier/cli/verify'
 require 'pact/pact_broker'
 require 'pact/cli/run_pact_verification'
+require 'ostruct'
 
 describe "pact-provider-verifier with pact broker config" do
   before do
diff --git a/spec/lib/pact/provider_verifier/aggregate_pact_configs_spec.rb b/spec/lib/pact/provider_verifier/aggregate_pact_configs_spec.rb
index 3c06c2e..d2354a2 100644
--- a/spec/lib/pact/provider_verifier/aggregate_pact_configs_spec.rb
+++ b/spec/lib/pact/provider_verifier/aggregate_pact_configs_spec.rb
@@ -1,4 +1,5 @@
 require 'pact/provider_verifier/aggregate_pact_configs'
+require 'ostruct'
 
 module Pact
   module ProviderVerifier
diff --git a/spec/support/message_producer_verifier.ru b/spec/support/message_producer_verifier.ru
index 63c16f7..255e287 100644
--- a/spec/support/message_producer_verifier.ru
+++ b/spec/support/message_producer_verifier.ru
@@ -1,6 +1,7 @@
 # TODO provider states
 
 require 'json'
+require 'ostruct'
 
 class Provider
   def a_test_message
@@ -31,7 +32,7 @@ class HttpRequestHandler
     request_body = JSON.parse(env['rack.input'].read)
     message_descriptor = OpenStruct.new(request_body)
     response_body = @message_creator.create(message_descriptor)
-    [200, {'Content-Type' => 'application/json'}, [response_body.to_json]]
+    [200, {'content-type' => 'application/json'}, [response_body.to_json]]
   end
 
 end
diff --git a/spec/support/provider-echo-host.ru b/spec/support/provider-echo-host.ru
index 2f07d7f..b9b8d7d 100644
--- a/spec/support/provider-echo-host.ru
+++ b/spec/support/provider-echo-host.ru
@@ -2,5 +2,5 @@ require 'json'
 
 run -> (env) {
   body = {"Host" => env['HTTP_HOST']}.to_json
-  [200, {"Content-Type" => "application/json"}, [body]]
+  [200, {"content-type" => "application/json"}, [body]]
 }
diff --git a/spec/support/provider_with_self_signed_cert.rb b/spec/support/provider_with_self_signed_cert.rb
index 1bc9366..44305ba 100644
--- a/spec/support/provider_with_self_signed_cert.rb
+++ b/spec/support/provider_with_self_signed_cert.rb
@@ -3,7 +3,7 @@
 def run_provider_with_self_signed_cert port
   # trap 'INT' do @server.shutdown end
   require 'rack'
-  require 'rack/handler/webrick'
+  require_relative 'webbrick'
   require 'webrick/https'
 
   webrick_opts = {:Port => port, :SSLEnable => true, :SSLCertName => [%w[CN localhost]]}
diff --git a/spec/support/webbrick.rb b/spec/support/webbrick.rb
new file mode 100644
index 0000000..be74e33
--- /dev/null
+++ b/spec/support/webbrick.rb
@@ -0,0 +1,11 @@
+module Rack
+  module Handler
+      begin
+        require 'rack/handler/webrick'
+        WEBrick = Class.new(Rack::Handler::WEBrick)
+      rescue LoadError
+        require 'rackup/handler/webrick'
+        WEBrick = Class.new(Rackup::Handler::WEBrick)
+      end
+  end
+end
\ No newline at end of file