diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index cf0e3dd..a818c78 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -1889,8 +1889,7 @@ function drupal_handle_request($test_only = FALSE) {
     exit;
   }
 
-  // @todo Figure out how best to handle the Kernel constructor parameters.
-  $kernel = new DrupalKernel('prod', FALSE, drupal_classloader(), !$test_only);
+  $kernel = new DrupalKernel('prod', drupal_classloader(), !$test_only);
 
   // @todo Remove this once everything in the bootstrap has been
   //   converted to services in the DIC.
@@ -2026,7 +2025,7 @@ function _drupal_bootstrap_kernel() {
   // Normally, index.php puts a container in drupal_container() by creating a
   // kernel. If there is no container yet, create one.
   if (!drupal_container()) {
-    $kernel = new DrupalKernel('prod', FALSE, drupal_classloader());
+    $kernel = new DrupalKernel('prod', drupal_classloader());
     $kernel->boot();
   }
 }
diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 7d2286a..34936d0 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -354,7 +354,7 @@ function install_begin_request(&$install_state) {
   // @see drupal_install_config_directories()
   // @see install_settings_form_submit()
   if ($install_state['settings_verified']) {
-    $kernel = new DrupalKernel('install', FALSE, drupal_classloader(), FALSE);
+    $kernel = new DrupalKernel('install', drupal_classloader(), FALSE);
     $kernel->boot();
     $container = $kernel->getContainer();
     // Add the file translation service to the container.
diff --git a/core/includes/install.inc b/core/includes/install.inc
index b0ca296..e0e86cc 100644
--- a/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -619,7 +619,7 @@ function drupal_install_system() {
 
   if (!drupal_container()->has('kernel')) {
     // Immediately boot a kernel to have real services ready.
-    $kernel = new DrupalKernel('install', FALSE, drupal_classloader(), FALSE);
+    $kernel = new DrupalKernel('install', drupal_classloader(), FALSE);
     $kernel->boot();
   }
 
diff --git a/core/includes/update.inc b/core/includes/update.inc
index 881adcd..fe83e31 100644
--- a/core/includes/update.inc
+++ b/core/includes/update.inc
@@ -116,7 +116,7 @@ function update_prepare_d8_bootstrap() {
 
   // Bootstrap the kernel.
   // Do not attempt to dump and write it.
-  $kernel = new DrupalKernel('update', FALSE, drupal_classloader(), FALSE);
+  $kernel = new DrupalKernel('update', drupal_classloader(), FALSE);
   $kernel->boot();
 
   // If any of the required settings needs to be written, then settings.php
@@ -439,7 +439,7 @@ function update_prepare_d8_bootstrap() {
   $settings = settings()->getAll();
   unset($settings['cache']['default']);
   new Settings($settings);
-  $kernel = new DrupalKernel('update', FALSE, drupal_classloader(), FALSE);
+  $kernel = new DrupalKernel('update', drupal_classloader(), FALSE);
   $kernel->boot();
 }
 
diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index 090fa69..af1fe52 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -53,13 +53,6 @@ class DrupalKernel implements DrupalKernelInterface, TerminableInterface {
   protected $environment;
 
   /**
-   * Whether we are in debug mode.
-   *
-   * @var bool
-   */
-  protected $debug;
-
-  /**
    * Whether the kernel has been booted.
    *
    * @var bool
@@ -157,10 +150,6 @@ class DrupalKernel implements DrupalKernelInterface, TerminableInterface {
    *   String indicating the environment, e.g. 'prod' or 'dev'. Used by
    *   Symfony\Component\HttpKernel\Kernel::__construct(). Drupal does not use
    *   this value currently. Pass 'prod'.
-   * @param bool $debug
-   *   Boolean indicating whether we are in debug mode. Used by
-   *   Symfony\Component\HttpKernel\Kernel::__construct(). Drupal does not use
-   *   this value currently. Pass TRUE.
    * @param \Symfony\Component\ClassLoader\ClassLoader $class_loader
    *   (optional) The classloader is only used if $storage is not given or
    *   the load from storage fails and a container rebuild is required. In
@@ -170,9 +159,8 @@ class DrupalKernel implements DrupalKernelInterface, TerminableInterface {
    *   (optional) FALSE to stop the container from being written to or read
    *   from disk. Defaults to TRUE.
    */
-  public function __construct($environment, $debug, ClassLoader $class_loader, $allow_dumping = TRUE) {
+  public function __construct($environment, ClassLoader $class_loader, $allow_dumping = TRUE) {
     $this->environment = $environment;
-    $this->debug = (Boolean) $debug;
     $this->booted = false;
     $this->classLoader = $class_loader;
     $this->allowDumping = $allow_dumping;
@@ -182,15 +170,15 @@ public function __construct($environment, $debug, ClassLoader $class_loader, $al
    * {@inheritdoc}
    */
   public function serialize() {
-    return serialize(array($this->environment, $this->debug, $this->classLoader, $this->allowDumping));
+    return serialize(array($this->environment, $this->classLoader, $this->allowDumping));
   }
 
   /**
    * {@inheritdoc}
    */
   public function unserialize($data) {
-    list($environment, $debug, $class_loader, $allow_dumping) = unserialize($data);
-    $this->__construct($environment, $debug, $class_loader, $allow_dumping);
+    list($environment, $class_loader, $allow_dumping) = unserialize($data);
+    $this->__construct($environment, $class_loader, $allow_dumping);
   }
 
   /**
@@ -210,20 +198,18 @@ public function boot() {
   /**
    * {@inheritdoc}
    */
-  public function shutdown()
-  {
-    if (false === $this->booted) {
+  public function shutdown() {
+    if (FALSE === $this->booted) {
       return;
     }
-    $this->booted = false;
+    $this->booted = FALSE;
     $this->container = null;
   }
 
   /**
    * {@inheritdoc}
    */
-  public function getContainer()
-  {
+  public function getContainer() {
     return $this->container;
   }
 
@@ -289,9 +275,8 @@ public function getServiceProviders() {
   /**
    * {@inheritdoc}
    */
-  public function terminate(Request $request, Response $response)
-  {
-    if (false === $this->booted) {
+  public function terminate(Request $request, Response $response) {
+    if (FALSE === $this->booted) {
       return;
     }
 
@@ -303,9 +288,8 @@ public function terminate(Request $request, Response $response)
   /**
    * {@inheritdoc}
    */
-  public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true)
-  {
-    if (false === $this->booted) {
+  public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true) {
+    if (FALSE === $this->booted) {
       $this->boot();
     }
 
@@ -364,13 +348,13 @@ public function updateModules(array $module_list, array $module_filenames = arra
   }
 
   /**
-   * Returns the classname based on environment, debug and testing prefix.
+   * Returns the classname based on environment and testing prefix.
    *
    * @return string
    *   The class name.
    */
   protected function getClassName() {
-    $parts = array('service_container', $this->environment, $this->debug);
+    $parts = array('service_container', $this->environment);
     // Make sure to use a testing-specific container even in the parent site.
     if (!empty($GLOBALS['drupal_test_info']['test_run_id'])) {
       $parts[] = $GLOBALS['drupal_test_info']['test_run_id'];
@@ -387,12 +371,10 @@ protected function getClassName() {
    *
    * @return array An array of kernel parameters
    */
-  protected function getKernelParameters()
-  {
+  protected function getKernelParameters() {
     return array(
-      'kernel.environment'     => $this->environment,
-      'kernel.debug'           => $this->debug,
-      );
+      'kernel.environment' => $this->environment,
+    );
   }
 
   /**
@@ -622,8 +604,7 @@ protected function dumpDrupalContainer(ContainerBuilder $container, $baseClass)
    *
    * @return HttpKernel
    */
-  protected function getHttpKernel()
-  {
+  protected function getHttpKernel() {
     return $this->container->get('http_kernel');
   }
 
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php
index 8a79ed2..e54e121 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php
@@ -98,7 +98,7 @@ protected function setUp() {
 
     // Bootstrap the kernel.
     // No need to dump it; this test runs in-memory.
-    $this->kernel = new DrupalKernel('unit_testing', TRUE, drupal_classloader(), FALSE);
+    $this->kernel = new DrupalKernel('unit_testing', drupal_classloader(), FALSE);
     $this->kernel->boot();
 
     // Collect and set a fixed module list.
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
index 74c8d44..818b7b0 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -993,7 +993,7 @@ protected function prepareConfigDirectories() {
    * @see TestBase::tearDown()
    */
   protected function rebuildContainer() {
-    $this->kernel = new DrupalKernel('testing', FALSE, drupal_classloader(), FALSE);
+    $this->kernel = new DrupalKernel('testing', drupal_classloader(), FALSE);
     $this->kernel->boot();
     // DrupalKernel replaces the container in drupal_container() with a
     // different object, so we need to replace the instance on this test class.
diff --git a/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php b/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php
index a73c6db..db60d18 100644
--- a/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php
@@ -49,12 +49,12 @@ function testCompileDIC() {
       'system' => 'system',
       'user' => 'user',
     );
-    $kernel = new DrupalKernel('testing', FALSE, $classloader);
+    $kernel = new DrupalKernel('testing', $classloader);
     $kernel->updateModules($module_enabled);
     $kernel->boot();
     // Instantiate it a second time and we should get the compiled Container
     // class.
-    $kernel = new DrupalKernel('testing', FALSE, $classloader);
+    $kernel = new DrupalKernel('testing', $classloader);
     $kernel->updateModules($module_enabled);
     $kernel->boot();
     $container = $kernel->getContainer();
@@ -68,7 +68,7 @@ function testCompileDIC() {
     // environment.
     global $conf;
     $conf['php_storage']['service_container']['class'] = 'Drupal\Component\PhpStorage\FileReadOnlyStorage';
-    $kernel = new DrupalKernel('testing', FALSE, $classloader);
+    $kernel = new DrupalKernel('testing', $classloader);
     $kernel->updateModules($module_enabled);
     $kernel->boot();
     $container = $kernel->getContainer();
@@ -91,12 +91,12 @@ function testCompileDIC() {
     // Add another module so that we can test that the new module's bundle is
     // registered to the new container.
     $module_enabled['service_provider_test'] = 'service_provider_test';
-    $kernel = new DrupalKernel('testing', FALSE, $classloader);
+    $kernel = new DrupalKernel('testing', $classloader);
     $kernel->updateModules($module_enabled);
     $kernel->boot();
     // Instantiate it a second time and we should still get a ContainerBuilder
     // class because we are using the read-only PHP storage.
-    $kernel = new DrupalKernel('testing', FALSE, $classloader);
+    $kernel = new DrupalKernel('testing', $classloader);
     $kernel->updateModules($module_enabled);
     $kernel->boot();
     $container = $kernel->getContainer();
@@ -119,7 +119,7 @@ function testCompileDIC() {
    */
   public function testSerialization() {
     $classloader = drupal_classloader();
-    $kernel = new DrupalKernel('testing', FALSE, $classloader);
+    $kernel = new DrupalKernel('testing', $classloader);
 
     $string = serialize($kernel);
     $unserialized_kernel = unserialize($string);
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/IgnoreSlaveSubscriberTest.php b/core/modules/system/lib/Drupal/system/Tests/System/IgnoreSlaveSubscriberTest.php
index bf004f9..da65377 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/IgnoreSlaveSubscriberTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/IgnoreSlaveSubscriberTest.php
@@ -38,7 +38,7 @@ function testSystemInitIgnoresSlaves() {
     Database::addConnectionInfo('default', 'slave', $connection_info['default']);
 
     db_ignore_slave();
-    $kernel = new DrupalKernel('testing', FALSE, drupal_classloader(), FALSE);
+    $kernel = new DrupalKernel('testing', drupal_classloader(), FALSE);
     $event = new GetResponseEvent($kernel, Request::create('http://example.com'), HttpKernelInterface::MASTER_REQUEST);
     $subscriber = new SlaveDatabaseIgnoreSubscriber();
     $subscriber->checkSlaveServer($event);