diff --git a/.editorconfig b/.editorconfig
index ddc5c02..0f99111 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -12,3 +12,6 @@ trim_trailing_whitespace = true
 
 [*.md]
 trim_trailing_whitespace = false
+
+[*.yml]
+indent_size = 2
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 598db63..753a724 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,46 +15,25 @@ permissions:
 jobs:
   testsuite:
     runs-on: ubuntu-24.04
-    strategy:
-      fail-fast: false
-      matrix:
-        php-version:
-          - '8.0'
 
     steps:
-    - uses: actions/checkout@v4
-
-    - name: Setup PHP
-      uses: shivammathur/setup-php@v2
-      with:
-        php-version: ${{ matrix.php-version }}
-        extensions: mbstring, intl
-        ini-values: zend.assertions = 1
-        coverage: pcov
+      - uses: actions/checkout@v4
+
+      - uses: php-actions/composer@v6
+        with:
+          php_version: '8.0'
+
+      - name: PHPUnit Tests
+        uses: php-actions/phpunit@v4
+        env:
+          TEST_NAME: Scarlett
+        with:
+          php_version: '8.0'
+          php_extensions: intl, mbstring, xdebug
+          version: '8.5'
+          coverage_clover: coverage.xml
+          configuration: phpunit.xml.dist
 
-    - name: Composer install
-      uses: ramsey/composer-install@v3
-      with:
-        dependency-versions: ${{ matrix.dependencies }}
-        composer-options: "${{ matrix.composer-options }}"
-
-    - name: Run PHPUnit
-      env:
-        XDEBUG_MODE: coverage
-      run: |
-        if [[ '${{ matrix.php-version }}' == '8.0' ]]; then
-          export CODECOVERAGE=1
-          vendor/bin/phpunit --coverage-clover=coverage.xml
-        else
-          vendor/bin/phpunit
-        fi
-
-    - name: Submit code coverage
-      if: matrix.php-version == '8.0'
-      uses: codecov/codecov-action@v5
-      with:
-        files: coverage.xml
-        token: ${{ secrets.CODECOV_TOKEN }}
 
   cs-stan:
     name: Coding Standard & Static Analysis