diff --git a/.circleci/config.yml b/.circleci/config.yml
deleted file mode 100644
index 097f9fb..0000000
--- a/.circleci/config.yml
+++ /dev/null
@@ -1,82 +0,0 @@
-version: 2.1
-executors:
-  ruby:
-    parameters:
-      version:
-        description: "Ruby version number"
-        default: "3.4.1"
-        type: string
-    docker:
-      - image: cimg/ruby:<< parameters.version >>
-
-commands:
-  bundle_install:
-    description: Install Ruby dependencies with Bundler
-    parameters:
-      version:
-        description: "Ruby version number"
-        default: "3.4.1"
-        type: string
-    steps:
-      - restore_cache:
-          keys:
-            - bundle-v1-{{ arch }}-<< parameters.version >>
-      - run:
-          name: Install Ruby Dependencies
-          command: |
-            gem install bundler -v 2.6.2 --conservative --no-document
-            bundle config --local path vendor/bundle
-            bundle check || (bundle install --jobs=4 --retry=3 && bundle clean)
-      - save_cache:
-          paths:
-            - ./vendor/bundle
-          key: bundle-v1-{{ arch }}-<< parameters.version >>-{{ checksum "Gemfile.lock" }}
-
-jobs:
-  rubocop:
-    executor: ruby
-    steps:
-      - checkout
-      - bundle_install
-      - run: bundle exec rubocop
-
-  test:
-    parameters:
-      version:
-        description: "Ruby version number"
-        default: "3.4.1"
-        type: string
-    executor:
-      name: ruby
-      version: << parameters.version >>
-    steps:
-      - checkout
-      - bundle_install:
-          version: << parameters.version >>
-      - run: bundle exec rake test
-      - store_test_results:
-          path: ./reports
-
-workflows:
-  version: 2
-  commit-workflow:
-    jobs:
-      - rubocop
-      - test:
-          matrix:
-            parameters:
-              version: ["3.2.6", "3.3.6", "3.4.1"]
-  cron-workflow:
-    jobs:
-      - rubocop
-      - test:
-          matrix:
-            parameters:
-              version: ["3.2.6", "3.3.6", "3.4.1"]
-    triggers:
-      - schedule:
-          cron: "0 13 * * 6"
-          filters:
-            branches:
-              only:
-                - main
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..c356f6c
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,53 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  rubocop:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 4.0.0
+      - name: Cache Ruby gems
+        uses: actions/cache@v3
+        with:
+          path: vendor/bundle
+          key: ${{ runner.os }}-bundle-4.0.0-${{ hashFiles('Gemfile.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-bundle-4.0.0-
+      - name: Install dependencies
+        run: |
+          bundle config set --local path vendor/bundle
+          bundle install --jobs 8 --retry 3
+      - name: Run RuboCop
+        run: bundle exec rubocop
+
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby-version: ["3.2.9", "3.3.10", "3.4.8", "4.0.0"]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+      - name: Cache Ruby gems
+        uses: actions/cache@v3
+        with:
+          path: vendor/bundle
+          key: ${{ runner.os }}-bundle-${{ matrix.ruby-version }}-${{ hashFiles('Gemfile.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-bundle-${{ matrix.ruby-version }}-
+      - name: Install dependencies
+        run: |
+          bundle config set --local path vendor/bundle
+          bundle install --jobs 8 --retry 3
+      - name: Run tests
+        run: bundle exec rake test
diff --git a/.ruby-version b/.ruby-version
index 47b322c..fcdb2e1 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.4.1
+4.0.0
diff --git a/Gemfile.lock b/Gemfile.lock
index 5fab1dc..ff21c8f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -70,6 +70,7 @@ PLATFORMS
   arm64-darwin-22
   arm64-darwin-23
   arm64-darwin-24
+  arm64-darwin-25
   x86_64-linux
 
 DEPENDENCIES
@@ -86,4 +87,4 @@ DEPENDENCIES
   wordexp!
 
 BUNDLED WITH
-   2.6.2
+   4.0.3