diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 0374a1c..02b07d9 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -25,7 +25,7 @@ jobs:
       - name: checkout
         uses: actions/checkout@v4
 
-      - uses: ruby/setup-ruby@50ba3386b050ad5b97a41fcb81240cbee1d1821f # pin@v1.188.0
+      - uses: ruby/setup-ruby@401c19e14f474b54450cd3905bb8b86e2c8509cf # pin@v1.204.0
         with:
           bundler-cache: true
 
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index c4d63c1..a3d396c 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -18,7 +18,7 @@ jobs:
       - name: checkout
         uses: actions/checkout@v4
 
-      - uses: ruby/setup-ruby@50ba3386b050ad5b97a41fcb81240cbee1d1821f # pin@v1.188.0
+      - uses: ruby/setup-ruby@401c19e14f474b54450cd3905bb8b86e2c8509cf # pin@v1.204.0
         with:
           bundler-cache: true
 
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 0285853..2b69694 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -20,7 +20,7 @@ jobs:
       - name: checkout
         uses: actions/checkout@v4
 
-      - uses: ruby/setup-ruby@50ba3386b050ad5b97a41fcb81240cbee1d1821f # pin@v1.188.0
+      - uses: ruby/setup-ruby@401c19e14f474b54450cd3905bb8b86e2c8509cf # pin@v1.204.0
         with:
           bundler-cache: true
 
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 8ab2267..d7d0ee7 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -22,7 +22,7 @@ jobs:
       - name: checkout
         uses: actions/checkout@v4
 
-      - uses: ruby/setup-ruby@50ba3386b050ad5b97a41fcb81240cbee1d1821f # pin@v1.188.0
+      - uses: ruby/setup-ruby@401c19e14f474b54450cd3905bb8b86e2c8509cf # pin@v1.204.0
         with:
           bundler-cache: true
           ruby-version: ${{ matrix.ruby }}
diff --git a/.ruby-version b/.ruby-version
index bea438e..9c25013 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.3.1
+3.3.6
diff --git a/spec/acceptance/github-server/Gemfile b/spec/acceptance/github-server/Gemfile
index 6d991bf..bee7c83 100644
--- a/spec/acceptance/github-server/Gemfile
+++ b/spec/acceptance/github-server/Gemfile
@@ -2,7 +2,8 @@
 
 source "https://rubygems.org"
 
-gem "rack", "= 2.2.8.1"
+gem "rack", "~> 3.1.8"
 gem "rack-test", "~> 2.1"
-gem "sinatra", "= 3.2.0"
+gem "rackup", "~> 2.2"
+gem "sinatra", "~> 4.1.1"
 gem "webrick", "~> 1.8"
diff --git a/spec/acceptance/github-server/web.rb b/spec/acceptance/github-server/web.rb
index b8ad149..6ff3928 100644
--- a/spec/acceptance/github-server/web.rb
+++ b/spec/acceptance/github-server/web.rb
@@ -8,18 +8,25 @@
 require "webrick/https"
 require "openssl"
 
-webrick_options = {
-  Host: "0.0.0.0",
-  Port: 443,
-  Logger: WEBrick::Log::new($stderr, WEBrick::Log::DEBUG),
-  SSLEnable: true,
-  SSLVerifyClient: OpenSSL::SSL::VERIFY_NONE,
-  SSLCertificate: OpenSSL::X509::Certificate.new(File.read("/acceptance/github-server/ssl.crt")),
-  SSLPrivateKey: OpenSSL::PKey::RSA.new(File.read("/acceptance/github-server/ssl.key")),
-  SSLCertName: [["CN", "github.fake"]]
-}
-
 class FakeGitHubApi < Sinatra::Base
+  use Rack::RewindableInput::Middleware
+
+  set :server, %w[webrick]
+  set :server_settings, {
+    Host: "0.0.0.0",
+    Port: 443,
+    Logger: WEBrick::Log::new($stderr, WEBrick::Log::DEBUG),
+    SSLEnable: true,
+    SSLVerifyClient: OpenSSL::SSL::VERIFY_NONE,
+    SSLCertificate: OpenSSL::X509::Certificate.new(File.read("/acceptance/github-server/ssl.crt")),
+    SSLPrivateKey: OpenSSL::PKey::RSA.new(File.read("/acceptance/github-server/ssl.key")),
+    SSLCertName: [["CN", "github.fake"]]
+  }
+
+  set :port, 443
+  set :bind, "0.0.0.0"
+  set :host_authorization, { permitted_hosts: [] }
+
   BASE_DIR = "/tmp/github"
 
   TEAM_MAP_FILE = File.join(BASE_DIR, "team_map.json")
@@ -405,4 +412,4 @@ def graphql_pending_query(query)
   end
 end
 
-Rack::Handler::WEBrick.run FakeGitHubApi, **webrick_options
+FakeGitHubApi.run!