diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1328d34..d87899c 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -26,6 +26,7 @@ jobs:
           - "3.2"
           - "3.3"
           - "3.4"
+          - "4.0"
         gemfile:
           - faraday_2
 
@@ -59,6 +60,31 @@ jobs:
 
       - run: bundle exec rubocop
 
+  yard:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          submodules: "true"
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ruby
+          bundler-cache: true
+
+      - name: bundle update
+        run: |
+          set -xe
+          bundle config path vendor/bundle
+          bundle update --jobs $(nproc) --retry 3
+
+      - name: yard generating test
+        run: |
+          set -xe
+          bundle exec yard
+          ls -ld doc/
+
   finish:
     needs: test
     runs-on: ubuntu-latest
diff --git a/Gemfile b/Gemfile
index 792eea4..f76e5f4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,4 +3,4 @@ source "https://rubygems.org"
 # Specify your gem's dependencies in chatwork.gemspec
 gemspec
 
-# eval_gemfile "#{__dir__}/gemfiles/common.gemfile"
+eval_gemfile "#{__dir__}/gemfiles/common.gemfile"
diff --git a/chatwork.gemspec b/chatwork.gemspec
index 770293e..982d590 100644
--- a/chatwork.gemspec
+++ b/chatwork.gemspec
@@ -29,11 +29,15 @@ Gem::Specification.new do |spec|
   spec.add_dependency "faraday-multipart", ">= 1.1.0"
 
   spec.add_development_dependency "activesupport"
+  spec.add_development_dependency "benchmark" # FIXME: Remove this after rubocop updated
   spec.add_development_dependency "bundler", ">= 1.3"
   spec.add_development_dependency "dotenv"
   spec.add_development_dependency "faraday_curl"
+  spec.add_development_dependency "irb"
   spec.add_development_dependency "onkcop", "1.0.0.0"
+  spec.add_development_dependency "ostruct" # FIXME: Remove this after rubocop updated
   spec.add_development_dependency "rake"
+  spec.add_development_dependency "rdoc"
   spec.add_development_dependency "rspec"
   spec.add_development_dependency "rspec-its"
   spec.add_development_dependency "rspec-parameterized"
diff --git a/gemfiles/common.gemfile b/gemfiles/common.gemfile
new file mode 100644
index 0000000..824d3bf
--- /dev/null
+++ b/gemfiles/common.gemfile
@@ -0,0 +1,3 @@
+# FIXME: Workaround for Ruby 4.0+
+# ref. https://github.com/banister/binding_of_caller/pull/90
+gem "binding_of_caller", github: "kivikakk/binding_of_caller", branch: "push-yrnnzolypxun"
diff --git a/gemfiles/faraday_2.gemfile b/gemfiles/faraday_2.gemfile
index 38a88d4..ea3a2dd 100644
--- a/gemfiles/faraday_2.gemfile
+++ b/gemfiles/faraday_2.gemfile
@@ -3,6 +3,6 @@ source "https://rubygems.org"
 # Specify your gem's dependencies in chatwork.gemspec
 gemspec path: "../"
 
-# eval_gemfile "#{__dir__}/common.gemfile"
+eval_gemfile "#{__dir__}/common.gemfile"
 
 gem "faraday", "~> 2.0"