diff -u b/core/lib/Drupal/Core/Cache/DatabaseBackend.php b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
--- b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
@@ -2,7 +2,7 @@
 
 namespace Drupal\Core\Cache;
 
-use Drupal\Component\Serialization\SerializationInterface;
+use Drupal\Component\Serialization\ObjectSerializationInterface;
 use Drupal\Component\Utility\Crypt;
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Database\SchemaObjectExistsException;
@@ -25,7 +25,7 @@
   /**
    * The serialization class to use.
    *
-   * @var \Drupal\Component\Serialization\SerializationInterface
+   * @var \Drupal\Component\Serialization\ObjectSerializationInterface
    */
   protected $serializer;
 
@@ -46,7 +46,7 @@
   /**
    * Constructs a DatabaseBackend object.
    *
-   * @param \Drupal\Component\Serialization\SerializationInterface $serializer
+   * @param \Drupal\Component\Serialization\ObjectSerializationInterface $serializer
    *   The serialization class to use.
    * @param \Drupal\Core\Database\Connection $connection
    *   The database connection.
@@ -55,7 +55,7 @@
    * @param string $bin
    *   The cache bin for which the object is created.
    */
-  public function __construct(SerializationInterface $serializer, Connection $connection, CacheTagsChecksumInterface $checksum_provider, $bin) {
+  public function __construct(ObjectSerializationInterface $serializer, Connection $connection, CacheTagsChecksumInterface $checksum_provider, $bin) {
     // All cache tables should be prefixed with 'cache_'.
     $bin = 'cache_' . $bin;
 
diff -u b/core/lib/Drupal/Core/Cache/DatabaseBackendFactory.php b/core/lib/Drupal/Core/Cache/DatabaseBackendFactory.php
--- b/core/lib/Drupal/Core/Cache/DatabaseBackendFactory.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseBackendFactory.php
@@ -2,7 +2,7 @@
 
 namespace Drupal\Core\Cache;
 
-use Drupal\Component\Serialization\SerializationInterface;
+use Drupal\Component\Serialization\ObjectSerializationInterface;
 use Drupal\Core\Database\Connection;
 
 class DatabaseBackendFactory implements CacheFactoryInterface {
@@ -31,14 +31,14 @@
   /**
    * Constructs the DatabaseBackendFactory object.
    *
-   * @param \Drupal\Component\Serialization\SerializationInterface $serializer
+   * @param \Drupal\Component\Serialization\ObjectSerializationInterface $serializer
    *   The serialization class to use.
    * @param \Drupal\Core\Database\Connection $connection
    *   Database connection
    * @param \Drupal\Core\Cache\CacheTagsChecksumInterface $checksum_provider
    *   The cache tags checksum provider.
    */
-  function __construct(SerializationInterface $serializer, Connection $connection, CacheTagsChecksumInterface $checksum_provider) {
+  function __construct(ObjectSerializationInterface $serializer, Connection $connection, CacheTagsChecksumInterface $checksum_provider) {
     $this->serializer = $serializer;
     $this->connection = $connection;
     $this->checksumProvider = $checksum_provider;
diff -u b/core/lib/Drupal/Core/Cache/MemoryBackend.php b/core/lib/Drupal/Core/Cache/MemoryBackend.php
--- b/core/lib/Drupal/Core/Cache/MemoryBackend.php
+++ b/core/lib/Drupal/Core/Cache/MemoryBackend.php
@@ -2,7 +2,7 @@
 
 namespace Drupal\Core\Cache;
 
-use Drupal\Component\Serialization\SerializationInterface;
+use Drupal\Component\Serialization\ObjectSerializationInterface;
 use Drupal\Core\DependencyInjection\DependencySerializationTrait;
 
 /**
@@ -24,7 +24,7 @@
   /**
    * The serialization class to use.
    *
-   * @var \Drupal\Component\Serialization\SerializationInterface
+   * @var \Drupal\Component\Serialization\ObjectSerializationInterface
    */
   protected $serializer;
 
@@ -36,10 +36,10 @@
   /**
    * Constructs a MemoryBackend object.
    *
-   * @param \Drupal\Component\Serialization\SerializationInterface $serializer
+   * @param \Drupal\Component\Serialization\ObjectSerializationInterface $serializer
    *   The serialization class to use.
    */
-  public function __construct(SerializationInterface $serializer) {
+  public function __construct(ObjectSerializationInterface $serializer) {
     $this->serializer = $serializer;
   }
 
diff -u b/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php b/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php
--- b/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php
+++ b/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php
@@ -2,14 +2,14 @@
 
 namespace Drupal\Core\Cache;
 
-use Drupal\Component\Serialization\SerializationInterface;
+use Drupal\Component\Serialization\ObjectSerializationInterface;
 
 class MemoryBackendFactory implements CacheFactoryInterface {
 
   /**
    * The serialization class to use.
    *
-   * @var \Drupal\Component\Serialization\SerializationInterface
+   * @var \Drupal\Component\Serialization\ObjectSerializationInterface
    */
   protected $serializer;
 
@@ -23,10 +23,10 @@
   /**
    * Constructs the MemoryBackendFactory object.
    *
-   * @param \Drupal\Component\Serialization\SerializationInterface $serializer
+   * @param \Drupal\Component\Serialization\ObjectSerializationInterface $serializer
    *   The serialization class to use.
    */
-  function __construct(SerializationInterface $serializer) {
+  function __construct(ObjectSerializationInterface $serializer) {
     $this->serializer = $serializer;
   }
 
only in patch2:
unchanged:
--- /dev/null
+++ b/core/lib/Drupal/Component/Serialization/ObjectSerializationInterface.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Drupal\Component\Serialization;
+
+/**
+ * Ensures that a serializer is usable for serializing PHP objects.
+ */
+interface ObjectSerializationInterface extends SerializationInterface {
+}
only in patch2:
unchanged:
--- a/core/lib/Drupal/Component/Serialization/PhpSerialize.php
+++ b/core/lib/Drupal/Component/Serialization/PhpSerialize.php
@@ -5,7 +5,7 @@
 /**
  * Default serialization for serialized PHP.
  */
-class PhpSerialize implements SerializationInterface {
+class PhpSerialize implements ObjectSerializationInterface {
 
   /**
    * {@inheritdoc}