diff -u b/core/tests/Drupal/Tests/Composer/Plugin/Scaffold/Fixtures.php b/core/tests/Drupal/Tests/Composer/Plugin/Scaffold/Fixtures.php
--- b/core/tests/Drupal/Tests/Composer/Plugin/Scaffold/Fixtures.php
+++ b/core/tests/Drupal/Tests/Composer/Plugin/Scaffold/Fixtures.php
@@ -301,7 +301,7 @@
   /**
    * Calls 'tearDown' in any test that copies fixtures to transient locations.
    */
-  protected function tearDown(): void {
+  public function tearDown() {
     // Remove any temporary directories that were created.
     $filesystem = new Filesystem();
     foreach ($this->tmpDirs as $dir) {