diff --git a/core/modules/system/lib/Drupal/system/Tests/Theme/TwigSettingsTest.php b/core/modules/system/lib/Drupal/system/Tests/Theme/TwigSettingsTest.php
index fe65c8f..b6c76c8 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Theme/TwigSettingsTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Theme/TwigSettingsTest.php
@@ -98,7 +98,8 @@ function testTwigCacheOverride() {
 
     // Get the template filename and the cache filename for
     // theme_test.template_test.html.twig.
-    $template_filename = $templates['theme_test_template_test']['path'] . '/' . $templates['theme_test_template_test']['template'] . $extension;
+    $info = $templates->get('theme_test_template_test');
+    $template_filename = $info['path'] . '/' . $info['template'] . $extension;
     $cache_filename = $this->container->get('twig')->getCacheFilename($template_filename);
 
     // Navigate to the page and make sure the template gets cached.