diff --git a/core/modules/system/lib/Drupal/system/Tests/System/ScriptTest.php b/core/modules/system/lib/Drupal/system/Tests/System/ScriptTest.php
index 9ba2e5c..773cfa0 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/ScriptTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/ScriptTest.php
@@ -45,6 +45,14 @@ public function testPasswordHashSh() {
    * Tests rebuild_token_calculator.sh.
    */
   public function testRebuildTokenCalculatorSh() {
+    // The script requires a settings.php with a hash salt setting.
+    $filename = $this->siteDirectory . '/settings.php';
+    touch($filename);
+    $settings['settings']['hash_salt'] = (object) array(
+      'value' => 'some_random_key',
+      'required' => TRUE,
+    );
+    drupal_rewrite_settings($settings, $filename);
     $_SERVER['argv'] = array(
       'core/scripts/rebuild_token_calculator.sh',
     );
diff --git a/core/scripts/rebuild_token_calculator.sh b/core/scripts/rebuild_token_calculator.sh
index 8168c2b..bcfd2b6 100755
--- a/core/scripts/rebuild_token_calculator.sh
+++ b/core/scripts/rebuild_token_calculator.sh
@@ -18,10 +18,11 @@
   return;
 }
 
-$autoloader = require __DIR__ . '/../vendor/autoload.php';
+require __DIR__ . '/../vendor/autoload.php';
+require_once __DIR__ . '/../includes/bootstrap.inc';
+
 $request = Request::createFromGlobals();
-$kernel = new DrupalKernel('prod', $autoloader);
-$kernel->boot($request);
+Settings::initialize(DrupalKernel::findSitePath($request));
 
 $timestamp = time();
 $token = Crypt::hmacBase64($timestamp, Settings::get('hash_salt'));