diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1c125aa..d802e14 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -47,7 +47,6 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php-version }}
-          extensions: fiber-amphp/ext-fiber@master
 
       - name: Fix OpenSSL config
         shell: bash
@@ -100,6 +99,7 @@ jobs:
         env:
           PHP_CS_FIXER_IGNORE_ENV: 1
         run: vendor/bin/php-cs-fixer --diff --dry-run -v fix
+        if: runner.os != 'Windows' && matrix.style-fix != 'none'
 
       - name: Install composer-require-checker
         run: php -r 'file_put_contents("composer-require-checker.phar", file_get_contents("https://github.com/maglnet/ComposerRequireChecker/releases/download/4.2.0/composer-require-checker.phar"));'