diff --git a/core/lib/Drupal/Core/DependencyInjection/DependencySerializationTrait.php b/core/lib/Drupal/Core/DependencyInjection/DependencySerializationTrait.php
index 26624a1..bb38d78 100644
--- a/core/lib/Drupal/Core/DependencyInjection/DependencySerializationTrait.php
+++ b/core/lib/Drupal/Core/DependencyInjection/DependencySerializationTrait.php
@@ -29,27 +29,14 @@ public function __sleep() {
     try {
       $container = \Drupal::getContainer();
       if ($container instanceof SleepHelperInterface) {
-        $hashes = $container->getHashes();
+        $sleep_helper_storage = $container->getSleepHelperStorage();
         foreach ($vars as $key => $value) {
-          if (is_object($value)) {
-            $service_id = FALSE;
-            // Special case the container.
-            if ($value instanceof ContainerInterface) {
-              $service_id = 'service_container';
-            }
-            else {
-              $hash = spl_object_hash($value);
-              if (isset($hashes[$hash])) {
-                $service_id = $hashes[$hash];
-              }
-            }
-            if ($service_id) {
-              // If a class member was instantiated by the dependency injection
-              // container, only store its ID so it can be used to get a fresh object
-              // on unserialization.
-              $this->_serviceIds[$key] = $service_id;
-              unset($vars[$key]);
-            }
+          if (is_object($value) && $sleep_helper_storage->contains($value)) {
+            // If a class member was instantiated by the dependency injection
+            // container, only store its ID so it can be used to get a fresh object
+            // on unserialization.
+            $this->_serviceIds[$key] = $sleep_helper_storage->offsetGet($value);
+            unset($vars[$key]);
           }
         }
       }
diff --git a/core/lib/Drupal/Core/DependencyInjection/SleepHelperInterface.php b/core/lib/Drupal/Core/DependencyInjection/SleepHelperInterface.php
index b7fab8c..c93a62e 100644
--- a/core/lib/Drupal/Core/DependencyInjection/SleepHelperInterface.php
+++ b/core/lib/Drupal/Core/DependencyInjection/SleepHelperInterface.php
@@ -11,11 +11,10 @@
 interface SleepHelperInterface {
 
   /**
-   * Get the SPL hashes of the services.
+   * Get an object storage containing the services.
    *
-   * When sleeping an object it becomes possible to investigate whether its
-   * properties are services.
+   * @return \SplObjectStorage
    */
-  public function getHashes();
+  public function getSleepHelperStorage();
 
 }
diff --git a/core/lib/Drupal/Core/DependencyInjection/SleepHelperTrait.php b/core/lib/Drupal/Core/DependencyInjection/SleepHelperTrait.php
index 02ec6dd..ad79132 100644
--- a/core/lib/Drupal/Core/DependencyInjection/SleepHelperTrait.php
+++ b/core/lib/Drupal/Core/DependencyInjection/SleepHelperTrait.php
@@ -13,18 +13,25 @@
  */
 trait SleepHelperTrait {
 
-  protected $hashes = [];
+  /**
+   * @var \SplObjectStorage
+   */
+  protected $sleepHelperStorage;
 
   /**
    * {@inheritdoc}
    */
-  public function getHashes() {
+  public function getSleepHelperStorage() {
+    if (empty($this->sleepHelperStorage)) {
+      $this->sleepHelperStorage = new \SplObjectStorage();
+      $this->sleepHelperStorage->attach($this, 'service_container');
+    }
     foreach ($this->services as $id => $service) {
       if (is_object($service)) {
-        $this->hashes[spl_object_hash($service)] = $id;
+        $this->sleepHelperStorage->attach($service, $id);
       }
     }
-    return $this->hashes;
+    return $this->sleepHelperStorage;
   }
 
   /**
@@ -32,8 +39,8 @@ public function getHashes() {
    *
    * @param array $hashes
    */
-  public function setHashes(array $hashes) {
-    $this->hashes = $hashes;
+  public function setSleepHelperStorage(\SplObjectStorage $storage) {
+    $this->sleepHelperStorage = $storage;
   }
 
 }
diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index e673618..aa1de8c 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -756,7 +756,7 @@ protected function initializeContainer() {
         $current_user_id = $this->container->get('current_user')->id();
       }
       // Save the current hashes.
-      $hashes = $this->container->getHashes();
+      $sleep_helper_storage = $this->container->getSleepHelperStorage();
 
       // If there is a session, close and save it.
       if ($this->container->initialized('session')) {
@@ -808,8 +808,8 @@ protected function initializeContainer() {
       }
     }
 
-    if (!empty($hashes)) {
-      $container->setHashes($hashes);
+    if (!empty($sleep_helper_storage )) {
+      $container->setSleepHelperStorage($sleep_helper_storage);
     }
     if (!empty($current_user_id)) {
       $this->container->get('current_user')->setInitialAccountId($current_user_id);
diff --git a/core/tests/Drupal/Tests/Core/DependencyInjection/ContainerTest.php b/core/tests/Drupal/Tests/Core/DependencyInjection/ContainerTest.php
index 3c88a0f..58a1492 100644
--- a/core/tests/Drupal/Tests/Core/DependencyInjection/ContainerTest.php
+++ b/core/tests/Drupal/Tests/Core/DependencyInjection/ContainerTest.php
@@ -28,14 +28,13 @@ public function testSerialize() {
   }
 
   /**
-   * @covers ::getHashes
+   * @covers ::getSleepHelperStorage
    */
   public function testGetHashes() {
     $container = new Container();
     $service = new BarClass();
     $container->set('bar', $service);
-    // Ensure the right hashes are returned.
-    $this->assertEquals([spl_object_hash($service) => 'bar'], $container->getHashes());
+    $this->assertEquals('bar', $container->getSleepHelperStorage()->offsetGet($service));
   }
 
 }