diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index 869d4ee..70024e2 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -36,6 +36,16 @@ class DrupalKernel extends Kernel {
   }
 
   /**
+   * Overrides Kernel::boot().
+   */
+  public function boot() {
+    // We bootstrap code here rather than init() so that we don't do the heavy
+    // code-load during a cache hit.
+    drupal_bootstrap(DRUPAL_BOOTSTRAP_CODE);
+    parent::boot();
+  }
+
+  /**
    * Returns an array of available bundles.
    */
   public function registerBundles() {
diff --git a/index.php b/index.php
index 38177ab..03724d2 100644
--- a/index.php
+++ b/index.php
@@ -25,7 +25,7 @@ define('DRUPAL_ROOT', getcwd());
 // @see Drupal\Core\EventSubscriber\PathSubscriber;
 // @see Drupal\Core\EventSubscriber\LegacyRequestSubscriber;
 require_once DRUPAL_ROOT . '/core/includes/bootstrap.inc';
-drupal_bootstrap(DRUPAL_BOOTSTRAP_CODE);
+drupal_bootstrap(DRUPAL_BOOTSTRAP_CONFIGURATION);
 
 // @todo Figure out how best to handle the Kernel constructor parameters.
 $kernel = new DrupalKernel('prod', FALSE);