diff --git a/core/modules/help_topics/tests/src/Functional/HelpTopicsSyntaxTest.php b/core/modules/help_topics/tests/src/Functional/HelpTopicsSyntaxTest.php
index 41a0f3c..7b1f76c 100644
--- a/core/modules/help_topics/tests/src/Functional/HelpTopicsSyntaxTest.php
+++ b/core/modules/help_topics/tests/src/Functional/HelpTopicsSyntaxTest.php
@@ -23,7 +23,7 @@ class HelpTopicsSyntaxTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'help',
     'help_topics',
   ];
@@ -183,7 +183,7 @@ protected function listDirectories($type) {
     // Find the extensions of this type, even if they are not installed, but
     // excluding test ones.
     $lister = \Drupal::service('extension.list.' . $type);
-    foreach ($lister->getAllAvailableInfo() as $name => $info) {
+    foreach (array_keys($lister->getAllAvailableInfo()) as $name) {
       $path = $lister->getPath($name);
       // You can tell test modules because they are in package 'Testing', but
       // test themes are only known by being found in test directories. So...