diff --git a/core/lib/Drupal/Core/Session/SessionManager.php b/core/lib/Drupal/Core/Session/SessionManager.php
index 1d470e2..04f3f99 100644
--- a/core/lib/Drupal/Core/Session/SessionManager.php
+++ b/core/lib/Drupal/Core/Session/SessionManager.php
@@ -124,16 +124,6 @@ public function start() {
     }
 
     if (empty($result)) {
-      // Randomly generate a session identifier for this request. This is
-      // necessary because \Drupal\user\SharedTempStoreFactory::get() wants to
-      // know the future session ID of a lazily started session in advance.
-      //
-      // @todo: With current versions of PHP there is little reason to generate
-      //   the session id from within application code. Consider using the
-      //   default php session id instead of generating a custom one:
-      //   https://www.drupal.org/node/2238561
-      $this->setId(Crypt::randomBytesBase64());
-
       // Initialize the session global and attach the Symfony session bags.
       $_SESSION = array();
       $this->loadSession();
@@ -223,7 +213,7 @@ public function regenerate($destroy = FALSE, $lifetime = NULL) {
     if ($this->isStarted()) {
       $old_session_id = $this->getId();
     }
-    session_id(Crypt::randomBytesBase64());
+    session_regenerate_id();
 
     $this->getMetadataBag()->clearCsrfTokenSeed();
 
diff --git a/core/modules/user/src/PrivateTempStore.php b/core/modules/user/src/PrivateTempStore.php
index 79be710..5491e92 100644
--- a/core/modules/user/src/PrivateTempStore.php
+++ b/core/modules/user/src/PrivateTempStore.php
@@ -7,11 +7,11 @@
 
 namespace Drupal\user;
 
+use Drupal\Component\Utility\Crypt;
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\KeyValueStore\KeyValueStoreExpirableInterface;
 use Drupal\Core\Lock\LockBackendInterface;
 use Drupal\Core\Session\AccountProxyInterface;
-use Symfony\Component\HttpFoundation\RequestStack;
 
 /**
  * Stores and retrieves temporary data for a given owner.
@@ -56,13 +56,6 @@ class PrivateTempStore {
   protected $currentUser;
 
   /**
-   * The request stack.
-   *
-   * @var \Symfony\Component\HttpFoundation\RequestStack
-   */
-  protected $requestStack;
-
-  /**
    * The time to live for items in seconds.
    *
    * By default, data is stored for one week (604800 seconds) before expiring.
@@ -80,16 +73,15 @@ class PrivateTempStore {
    *   of key/value pairs.
    * @param \Drupal\Core\Lock\LockBackendInterface $lockBackend
    *   The lock object used for this data.
-   * @param mixed $owner
-   *   The owner key to store along with the data (e.g. a user or session ID).
+   * @param \Drupal\Core\Session\AccountProxyInterface $current_user
+   *   The current user.
    * @param int $expire
    *   The time to live for items, in seconds.
    */
-  public function __construct(KeyValueStoreExpirableInterface $storage, LockBackendInterface $lockBackend, AccountProxyInterface $current_user, RequestStack $request_stack, $expire = 604800) {
+  public function __construct(KeyValueStoreExpirableInterface $storage, LockBackendInterface $lockBackend, AccountProxyInterface $current_user, $expire = 604800) {
     $this->storage = $storage;
     $this->lockBackend = $lockBackend;
     $this->currentUser = $current_user;
-    $this->requestStack = $request_stack;
     $this->expire = $expire;
   }
 
@@ -211,6 +203,15 @@ protected function createkey($key) {
    *   The owner.
    */
   protected function getOwner() {
-    return $this->currentUser->id() ?: $this->requestStack->getCurrentRequest()->getSession()->getId();
+    if ($this->currentUser->isAuthenticated()) {
+      return $this->currentUser->id();
+    }
+    // Anonymous users needs special handling.
+    // @todo Fix me.
+    if (!isset($_SESSION['user_private_owner'])) {
+      $_SESSION['user_private_owner'] = Crypt::randomBytesBase64();
+    }
+    return $_SESSION['user_private_owner'];
   }
+
 }
diff --git a/core/modules/user/src/PrivateTempStoreFactory.php b/core/modules/user/src/PrivateTempStoreFactory.php
index bd62633..52abbda 100644
--- a/core/modules/user/src/PrivateTempStoreFactory.php
+++ b/core/modules/user/src/PrivateTempStoreFactory.php
@@ -39,13 +39,6 @@ class PrivateTempStoreFactory {
   protected $currentUser;
 
   /**
-   * The request stack.
-   *
-   * @var \Symfony\Component\HttpFoundation\RequestStack
-   */
-  protected $requestStack;
-
-  /**
    * The time to live for items in seconds.
    *
    * @var int
@@ -55,18 +48,19 @@ class PrivateTempStoreFactory {
   /**
    * Constructs a Drupal\user\PrivateTempStoreFactory object.
    *
-   * @param \Drupal\Core\Database\Connection $connection
-   *   The connection object used for this data.
+   * @param \Drupal\Core\KeyValueStore\KeyValueExpirableFactoryInterface $storage_factory
+   *   The storage factory creating the backend to store the data.
    * @param \Drupal\Core\Lock\LockBackendInterface $lockBackend
    *   The lock object used for this data.
+   * @param \Drupal\Core\Session\AccountProxyInterface $current_user
+   *   The current user.
    * @param int $expire
    *   The time to live for items, in seconds.
    */
-  function __construct(KeyValueExpirableFactoryInterface $storage_factory, LockBackendInterface $lockBackend, AccountProxyInterface $current_user, RequestStack $request_stack, $expire = 604800) {
+  function __construct(KeyValueExpirableFactoryInterface $storage_factory, LockBackendInterface $lockBackend, AccountProxyInterface $current_user, $expire = 604800) {
     $this->storageFactory = $storage_factory;
     $this->lockBackend = $lockBackend;
     $this->currentUser = $current_user;
-    $this->requestStack = $request_stack;
     $this->expire = $expire;
   }
 
@@ -83,7 +77,7 @@ function __construct(KeyValueExpirableFactoryInterface $storage_factory, LockBac
   function get($collection) {
     // Store the data for this collection in the database.
     $storage = $this->storageFactory->get("user.private_tempstore.$collection");
-    return new PrivateTempStore($storage, $this->lockBackend, $this->currentUser, $this->requestStack, $this->expire);
+    return new PrivateTempStore($storage, $this->lockBackend, $this->currentUser, $this->expire);
   }
 
 }
diff --git a/core/modules/user/src/SharedTempStoreFactory.php b/core/modules/user/src/SharedTempStoreFactory.php
index da2331d..cf069d7 100644
--- a/core/modules/user/src/SharedTempStoreFactory.php
+++ b/core/modules/user/src/SharedTempStoreFactory.php
@@ -8,6 +8,7 @@
 namespace Drupal\user;
 
 use Drupal\Component\Serialization\SerializationInterface;
+use Drupal\Component\Utility\Crypt;
 use Drupal\Core\KeyValueStore\KeyValueExpirableFactoryInterface;
 use Drupal\Core\Lock\LockBackendInterface;
 use Symfony\Component\HttpFoundation\RequestStack;
@@ -82,7 +83,18 @@ function get($collection, $owner = NULL) {
     // Use the currently authenticated user ID or the active user ID unless
     // the owner is overridden.
     if (!isset($owner)) {
-      $owner = \Drupal::currentUser()->id() ?: session_id();
+      $account = \Drupal::currentUser();
+      if ($account->isAuthenticated()) {
+        $owner = $account->id();
+      }
+      else {
+        // Anonymous users needs special handling.
+        // @todo Fix me.
+        if (!isset($_SESSION['user_shared_owner'])) {
+          $_SESSION['user_shared_owner'] = Crypt::randomBytesBase64();
+        }
+        $owner = $_SESSION['user_shared_owner'];
+      }
     }
 
     // Store the data for this collection in the database.
diff --git a/core/modules/user/tests/src/Unit/PrivateTempStoreTest.php b/core/modules/user/tests/src/Unit/PrivateTempStoreTest.php
index a2d3d95..bd71c9f 100644
--- a/core/modules/user/tests/src/Unit/PrivateTempStoreTest.php
+++ b/core/modules/user/tests/src/Unit/PrivateTempStoreTest.php
@@ -10,7 +10,6 @@
 use Drupal\Tests\UnitTestCase;
 use Drupal\user\PrivateTempStore;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpFoundation\RequestStack;
 
 /**
  * @coversDefaultClass \Drupal\user\PrivateTempStore
@@ -47,13 +46,6 @@ class PrivateTempStoreTest extends UnitTestCase {
   protected $currentUser;
 
   /**
-   * The request stack.
-   *
-   * @var \Symfony\Component\HttpFoundation\RequestStack
-   */
-  protected $requestStack;
-
-  /**
    * A tempstore object belonging to the owner.
    *
    * @var \stdClass
@@ -80,11 +72,9 @@ protected function setUp() {
       ->method('id')
       ->willReturn(1);
 
-    $this->requestStack = new RequestStack();
     $request = Request::createFromGlobals();
-    $this->requestStack->push($request);
 
-    $this->tempStore = new PrivateTempStore($this->keyValue, $this->lock, $this->currentUser, $this->requestStack, 604800);
+    $this->tempStore = new PrivateTempStore($this->keyValue, $this->lock, $this->currentUser, 604800);
 
     $this->ownObject = (object) array(
       'data' => 'test_data',
diff --git a/core/modules/user/user.services.yml b/core/modules/user/user.services.yml
index 0a55b6e..838bb4f 100644
--- a/core/modules/user/user.services.yml
+++ b/core/modules/user/user.services.yml
@@ -50,7 +50,7 @@ services:
     arguments: ['@entity.manager', '@password']
   user.private_tempstore:
     class: Drupal\user\PrivateTempStoreFactory
-    arguments: ['@keyvalue.expirable', '@lock', '@current_user', '@request_stack', '%user.tempstore.expire%']
+    arguments: ['@keyvalue.expirable', '@lock', '@current_user', '%user.tempstore.expire%']
     tags:
       - { name: backend_overridable }
   user.shared_tempstore: