diff --git a/core/core.services.yml b/core/core.services.yml
index c8851dd..5613f5e 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -721,11 +721,6 @@ services:
     factory_service: authentication
     arguments: ['@request']
     synchronized: true
-  session_handler:
-    class: Drupal\Core\Session\SessionHandler
-    arguments: ['@request', '@database']
-    tags:
-      - { name: persist }
   asset.css.collection_renderer:
     class: Drupal\Core\Asset\CssCollectionRenderer
     arguments: [ '@state' ]
diff --git a/core/includes/session.inc b/core/includes/session.inc
index 96b141c..4c9b14b 100644
--- a/core/includes/session.inc
+++ b/core/includes/session.inc
@@ -9,7 +9,6 @@
 use Drupal\Component\Utility\Settings;
 use Drupal\Core\Session\AnonymousUserSession;
 use Drupal\Core\Session\SessionHandler;
-use Drupal\Core\Utility\Error;
 
 /**
  * Initializes the session handler, starting a session if needed.
@@ -22,7 +21,8 @@ function drupal_session_initialize() {
   }
 
   // Register the default session handler.
-  $handler = \Drupal::service('session_handler');
+  // @todo: Extract session storage from session handler into a service.
+  $handler = new SessionHandler(\Drupal::request(), \Drupal::database());
   session_set_save_handler($handler, TRUE);
 
   $is_https = \Drupal::request()->isSecure();
diff --git a/core/lib/Drupal/Core/Session/SessionHandler.php b/core/lib/Drupal/Core/Session/SessionHandler.php
index 2c4c9f9..8b51764 100644
--- a/core/lib/Drupal/Core/Session/SessionHandler.php
+++ b/core/lib/Drupal/Core/Session/SessionHandler.php
@@ -10,7 +10,6 @@
 use Drupal\Component\Utility\Crypt;
 use Drupal\Component\Utility\Settings;
 use Drupal\Core\Database\Connection;
-use Drupal\Core\DestructableInterface;
 use Drupal\Core\Utility\Error;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -62,9 +61,6 @@ public function open($save_path, $name) {
 
   /**
    * {@inheritdoc}
-   *
-   * Initializes the global $user object for the user associated with the
-   * session.
    */
   public function read($sid) {
     global $user;
@@ -79,16 +75,20 @@ public function read($sid) {
     }
 
     // Otherwise, if the session is still active, we have a record of the
-    // client's session in the database. If it's HTTPS then we are either have
-    // a HTTPS session or we are about to log in so we check the sessions table
+    // client's session in the database. If it's HTTPS then we are either have a
+    // HTTPS session or we are about to log in so we check the sessions table
     // for an anonymous session with the non-HTTPS-only cookie. The session ID
-    // that is in the user's cookie is hashed before being stored in the database
-    // as a security measure. Thus, we have to hash it to match the database.
+    // that is in the user's cookie is hashed before being stored in the
+    // database as a security measure. Thus, we have to hash it to match the
+    // database.
     if ($this->request->isSecure()) {
+      // Try to load a session using the HTTPS-only secure session id.
       $values = $this->connection->query("SELECT u.*, s.* FROM {users} u INNER JOIN {sessions} s ON u.uid = s.uid WHERE s.ssid = :ssid", array(
         ':ssid' => Crypt::hashBase64($sid),
       ))->fetchAssoc();
       if (!$values) {
+        // Fallback and try to load the anonymous non-HTTPS session. Use the
+        // non-HTTPS session id as the key.
         if ($cookies->has($insecure_session_name)) {
           $values = $this->connection->query("SELECT u.*, s.* FROM {users} u INNER JOIN {sessions} s ON u.uid = s.uid WHERE s.sid = :sid AND s.uid = 0", array(
             ':sid' => Crypt::hashBase64($cookies->get($insecure_session_name)),
@@ -97,6 +97,7 @@ public function read($sid) {
       }
     }
     else {
+      // Try to load a session using the non-HTTPS session id.
       $values = $this->connection->query("SELECT u.*, s.* FROM {users} u INNER JOIN {sessions} s ON u.uid = s.uid WHERE s.sid = :sid", array(
         ':sid' => Crypt::hashBase64($sid),
       ))->fetchAssoc();
@@ -143,14 +144,16 @@ public function write($sid, $value) {
     // manually.
     try {
       if (!drupal_save_session()) {
-        // We don't have anything to do if we are not allowed to save the session.
+        // We don't have anything to do if we are not allowed to save the
+        // session.
         return TRUE;
       }
       // Check whether $_SESSION has been changed in this request.
       $is_changed = empty($this->lastRead) || $this->lastRead['sid'] != $sid || $this->lastRead['value'] !== $value;
 
       // For performance reasons, do not update the sessions table, unless
-      // $_SESSION has changed or more than 180 has passed since the last update.
+      // $_SESSION has changed or more than 180 has passed since the last
+      // update.
       $needs_update = !$user->getLastAccessedTime() || REQUEST_TIME - $user->getLastAccessedTime() > Settings::get('session_write_interval', 180);
 
       if ($is_changed || $needs_update) {
@@ -170,8 +173,8 @@ public function write($sid, $value) {
           $key['ssid'] = Crypt::hashBase64($sid);
           $cookies = $this->request->cookies;
           // The "secure pages" setting allows a site to simultaneously use both
-          // secure and insecure session cookies. If enabled and both cookies are
-          // presented then use both keys. The session ID from the cookie is
+          // secure and insecure session cookies. If enabled and both cookies
+          // are presented then use both keys. The session ID from the cookie is
           // hashed before being stored in the database as a security measure.
           if (Settings::get('mixed_mode_sessions', FALSE)) {
             $insecure_session_name = substr(session_name(), 1);
@@ -192,7 +195,7 @@ public function write($sid, $value) {
       if ($user->isAuthenticated() && REQUEST_TIME - $user->getLastAccessedTime() > Settings::get('session_write_interval', 180)) {
         $this->connection->update('users')
           ->fields(array(
-            'access' => REQUEST_TIME
+            'access' => REQUEST_TIME,
           ))
           ->condition('uid', $user->id())
           ->execute();
@@ -201,8 +204,8 @@ public function write($sid, $value) {
     }
     catch (\Exception $exception) {
       require_once DRUPAL_ROOT . '/core/includes/errors.inc';
-      // If we are displaying errors, then do so with no possibility of a further
-      // uncaught exception being thrown.
+      // If we are displaying errors, then do so with no possibility of a
+      // further uncaught exception being thrown.
       if (error_displayable()) {
         print '<h1>Uncaught exception thrown in session handler.</h1>';
         print '<p>' . Error::renderExceptionSafe($exception) . '</p><hr />';