diff --git a/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php b/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php
index d698c4e..ba7a3cd 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php
@@ -125,10 +125,11 @@ public function testCacheFilename() {
     $this->assertGreaterThan(TwigPhpStorageCache::SUFFIX_SUBSTRING_LENGTH, strlen(basename($long_name)));
     $class = $environment->getTemplateClass($long_name);
     $key = $cache->generateKey($long_name, $class);
-    $hash = $this->container->getParameter('twig_extension_hash');
-    // The key should consist of the hash, two underscores, and two strings
-    // truncated to length TwigPhpStorageCache::SUFFIX_SUBSTRING_LENGTH.
-    $expected = strlen($hash) + 2 + 2 * TwigPhpStorageCache::SUFFIX_SUBSTRING_LENGTH;
+    $prefix = $environment->getTwigCachePrefix();
+    // The key should consist of the prefix, an underscore, and two strings
+    // each truncated to length TwigPhpStorageCache::SUFFIX_SUBSTRING_LENGTH
+    // separated by an underscore.
+    $expected = strlen($prefix) + 2 + 2 * TwigPhpStorageCache::SUFFIX_SUBSTRING_LENGTH;
     $this->assertEquals($expected, strlen($key));
 
     $original_filename = $environment->getCacheFilename('core/modules/system/templates/container.html.twig');