diff --git a/core/core.services.yml b/core/core.services.yml
index 62a0f3e..2f160ef 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -1584,3 +1584,69 @@ services:
     arguments: ['@current_user', '@path.current', '@path.matcher', '@language_manager']
     tags:
       - { name: event_subscriber }
+
+  serializer:
+    class: Symfony\Component\Serializer\Serializer
+    arguments: [{  }, {  }]
+  serializer.normalizer.config_entity:
+    class: Drupal\Core\Serialization\Normalizer\ConfigEntityNormalizer
+    tags:
+      - { name: normalizer }
+    arguments: ['@entity.manager']
+  serializer.normalizer.content_entity:
+      class: Drupal\Core\Serialization\Normalizer\ContentEntityNormalizer
+      tags:
+        - { name: normalizer }
+      arguments: ['@entity.manager']
+  serializer.normalizer.entity:
+    class: Drupal\Core\Serialization\Normalizer\EntityNormalizer
+    tags:
+      - { name: normalizer }
+    arguments: ['@entity.manager']
+  serializer.normalizer.complex_data:
+    class: Drupal\Core\Serialization\Normalizer\ComplexDataNormalizer
+    tags:
+      - { name: normalizer }
+  serializer.normalizer.entity_reference_field_item:
+    class: Drupal\Core\Serialization\Normalizer\EntityReferenceFieldItemNormalizer
+    tags:
+      # Set the priority lower than the hal entity reference field item
+      # normalizer, so that we do not replace that for hal_json.
+      # @todo Find a better way for this in https://www.drupal.org/node/2575761.
+      - { name: normalizer, priority: 5 }
+  serializer.normalizer.list:
+    class: Drupal\Core\Serialization\Normalizer\ListNormalizer
+    tags:
+      - { name: normalizer }
+  serializer.normalizer.password_field_item:
+      class: Drupal\Core\Serialization\Normalizer\NullNormalizer
+      arguments: ['Drupal\Core\Field\Plugin\Field\FieldType\PasswordItem']
+      tags:
+        - { name: normalizer, priority: 20 }
+  serializer.normalizer.safe_string:
+      class: Drupal\Core\Serialization\Normalizer\MarkupNormalizer
+      tags:
+        - { name: normalizer }
+  serializer.normalizer.typed_data:
+    class: Drupal\Core\Serialization\Normalizer\TypedDataNormalizer
+    tags:
+      - { name: normalizer }
+  serializer.encoder.json:
+    class: Drupal\Core\Serialization\Encoder\JsonEncoder
+    tags:
+      - { name: encoder, format: json }
+  serializer.encoder.xml:
+    class: Drupal\Core\Serialization\Encoder\XmlEncoder
+    tags:
+      - { name: encoder, format: xml }
+  serializer.entity_resolver:
+    class: Drupal\Core\Serialization\EntityResolver\ChainEntityResolver
+  serializer.entity_resolver.uuid:
+    class: Drupal\Core\Serialization\EntityResolver\UuidResolver
+    tags:
+      - { name: entity_resolver}
+    arguments: ['@entity.manager']
+  serialization.entity_resolver.target_id:
+    class: Drupal\Core\Serialization\EntityResolver\TargetIdResolver
+    tags:
+      - { name: entity_resolver}
diff --git a/core/modules/serialization/src/EntityResolver/ChainEntityResolver.php b/core/lib/Core/Serialization/EntityResolver/ChainEntityResolver.php
similarity index 76%
rename from core/modules/serialization/src/EntityResolver/ChainEntityResolver.php
rename to core/lib/Core/Serialization/EntityResolver/ChainEntityResolver.php
index 669dcb5..ca065ec 100644
--- a/core/modules/serialization/src/EntityResolver/ChainEntityResolver.php
+++ b/core/lib/Core/Serialization/EntityResolver/ChainEntityResolver.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\EntityResolver\ChainEntityResolver.
+ * Contains \Drupal\Core\Serialization\EntityResolver\ChainEntityResolver.
  */
 
-namespace Drupal\serialization\EntityResolver;
+namespace Drupal\Core\Serialization\EntityResolver;
 
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 
@@ -17,14 +17,14 @@ class ChainEntityResolver implements ChainEntityResolverInterface {
   /**
    * The concrete resolvers.
    *
-   * @var \Drupal\serialization\EntityResolver\EntityResolverInterface[]
+   * @var \Drupal\Core\Serialization\EntityResolver\EntityResolverInterface[]
    */
   protected $resolvers = array();
 
   /**
    * Constructs a ChainEntityResolver object.
    *
-   * @param \Drupal\serialization\EntityResolver\EntityResolverInterface[] $resolvers
+   * @param \Drupal\Core\Serialization\EntityResolver\EntityResolverInterface[] $resolvers
    *   The array of concrete resolvers.
    */
   public function __construct(array $resolvers = array()) {
diff --git a/core/modules/serialization/src/EntityResolver/ChainEntityResolverInterface.php b/core/lib/Core/Serialization/EntityResolver/ChainEntityResolverInterface.php
similarity index 59%
copy from core/modules/serialization/src/EntityResolver/ChainEntityResolverInterface.php
copy to core/lib/Core/Serialization/EntityResolver/ChainEntityResolverInterface.php
index 205d1ff..26d7d7a 100644
--- a/core/modules/serialization/src/EntityResolver/ChainEntityResolverInterface.php
+++ b/core/lib/Core/Serialization/EntityResolver/ChainEntityResolverInterface.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\EntityResolver\ChainEntityResolverInterface.
+ * Contains \Drupal\Core\Serialization\EntityResolver\ChainEntityResolverInterface.
  */
 
-namespace Drupal\serialization\EntityResolver;
+namespace Drupal\Core\Serialization\EntityResolver;
 
 /**
  * An interface for delegating a entity resolution to a chain of resolvers.
@@ -15,7 +15,7 @@
   /**
    * Adds an entity resolver.
    *
-   * @param \Drupal\serialization\EntityResolver\EntityResolverInterface $resolver
+   * @param \Drupal\Core\Serialization\EntityResolver\EntityResolverInterface $resolver
    *   The entity resolver to add.
    */
   public function addResolver(EntityResolverInterface $resolver);
diff --git a/core/modules/serialization/src/EntityResolver/EntityResolverInterface.php b/core/lib/Core/Serialization/EntityResolver/EntityResolverInterface.php
similarity index 92%
copy from core/modules/serialization/src/EntityResolver/EntityResolverInterface.php
copy to core/lib/Core/Serialization/EntityResolver/EntityResolverInterface.php
index 883bb8b..56fd2f4 100644
--- a/core/modules/serialization/src/EntityResolver/EntityResolverInterface.php
+++ b/core/lib/Core/Serialization/EntityResolver/EntityResolverInterface.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\EntityResolver\EntityResolverInterface.
+ * Contains \Drupal\Core\Serialization\EntityResolver\EntityResolverInterface.
  */
 
-namespace Drupal\serialization\EntityResolver;
+namespace Drupal\Core\Serialization\EntityResolver;
 
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 
diff --git a/core/modules/serialization/src/EntityResolver/TargetIdResolver.php b/core/lib/Core/Serialization/EntityResolver/TargetIdResolver.php
similarity index 78%
rename from core/modules/serialization/src/EntityResolver/TargetIdResolver.php
rename to core/lib/Core/Serialization/EntityResolver/TargetIdResolver.php
index 43ff245..a7e7855 100644
--- a/core/modules/serialization/src/EntityResolver/TargetIdResolver.php
+++ b/core/lib/Core/Serialization/EntityResolver/TargetIdResolver.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\EntityResolver\TargetIdResolver.
+ * Contains \Drupal\Core\Serialization\EntityResolver\TargetIdResolver.
  */
 
-namespace Drupal\serialization\EntityResolver;
+namespace Drupal\Core\Serialization\EntityResolver;
 
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 
diff --git a/core/modules/serialization/src/EntityResolver/UuidReferenceInterface.php b/core/lib/Core/Serialization/EntityResolver/UuidReferenceInterface.php
similarity index 77%
copy from core/modules/serialization/src/EntityResolver/UuidReferenceInterface.php
copy to core/lib/Core/Serialization/EntityResolver/UuidReferenceInterface.php
index 632eef4..6b24b20 100644
--- a/core/modules/serialization/src/EntityResolver/UuidReferenceInterface.php
+++ b/core/lib/Core/Serialization/EntityResolver/UuidReferenceInterface.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\EntityResolver\UuidReferenceInterface.
+ * Contains \Drupal\Core\Serialization\EntityResolver\UuidReferenceInterface.
  */
 
-namespace Drupal\serialization\EntityResolver;
+namespace Drupal\Core\Serialization\EntityResolver;
 
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 
diff --git a/core/modules/serialization/src/EntityResolver/UuidResolver.php b/core/lib/Core/Serialization/EntityResolver/UuidResolver.php
similarity index 91%
rename from core/modules/serialization/src/EntityResolver/UuidResolver.php
rename to core/lib/Core/Serialization/EntityResolver/UuidResolver.php
index 043fdfd..49047e6 100644
--- a/core/modules/serialization/src/EntityResolver/UuidResolver.php
+++ b/core/lib/Core/Serialization/EntityResolver/UuidResolver.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\EntityResolver\UuidResolver.
+ * Contains \Drupal\Core\Serialization\EntityResolver\UuidResolver.
  */
 
-namespace Drupal\serialization\EntityResolver;
+namespace Drupal\Core\Serialization\EntityResolver;
 
 use Drupal\Core\Entity\EntityManagerInterface;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
diff --git a/core/modules/serialization/src/Normalizer/ComplexDataNormalizer.php b/core/lib/Core/Serialization/Normalizer/ComplexDataNormalizer.php
similarity index 89%
rename from core/modules/serialization/src/Normalizer/ComplexDataNormalizer.php
rename to core/lib/Core/Serialization/Normalizer/ComplexDataNormalizer.php
index 3267425..e07eedf 100644
--- a/core/modules/serialization/src/Normalizer/ComplexDataNormalizer.php
+++ b/core/lib/Core/Serialization/Normalizer/ComplexDataNormalizer.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\ComplexDataNormalizer.
+ * Contains \Drupal\Core\Serialization\Normalizer\ComplexDataNormalizer.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 /**
  * Converts the Drupal entity object structures to a normalized array.
diff --git a/core/modules/serialization/src/Normalizer/ConfigEntityNormalizer.php b/core/lib/Core/Serialization/Normalizer/ConfigEntityNormalizer.php
similarity index 80%
rename from core/modules/serialization/src/Normalizer/ConfigEntityNormalizer.php
rename to core/lib/Core/Serialization/Normalizer/ConfigEntityNormalizer.php
index 913672c..317c15a 100644
--- a/core/modules/serialization/src/Normalizer/ConfigEntityNormalizer.php
+++ b/core/lib/Core/Serialization/Normalizer/ConfigEntityNormalizer.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\ConfigEntityNormalizer.
+ * Contains \Drupal\Core\Serialization\Normalizer\ConfigEntityNormalizer.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 /**
  * Normalizes/denormalizes Drupal config entity objects into an array structure.
diff --git a/core/modules/serialization/src/Normalizer/ContentEntityNormalizer.php b/core/lib/Core/Serialization/Normalizer/ContentEntityNormalizer.php
similarity index 86%
rename from core/modules/serialization/src/Normalizer/ContentEntityNormalizer.php
rename to core/lib/Core/Serialization/Normalizer/ContentEntityNormalizer.php
index 8ed3c91..c135068 100644
--- a/core/modules/serialization/src/Normalizer/ContentEntityNormalizer.php
+++ b/core/lib/Core/Serialization/Normalizer/ContentEntityNormalizer.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\ContentEntityNormalizer.
+ * Contains \Drupal\Core\Serialization\Normalizer\ContentEntityNormalizer.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 /**
  * Normalizes/denormalizes Drupal content entities into an array structure.
diff --git a/core/modules/serialization/src/Normalizer/EntityNormalizer.php b/core/lib/Core/Serialization/Normalizer/EntityNormalizer.php
similarity index 96%
rename from core/modules/serialization/src/Normalizer/EntityNormalizer.php
rename to core/lib/Core/Serialization/Normalizer/EntityNormalizer.php
index e806ff6..3bb0cac 100644
--- a/core/modules/serialization/src/Normalizer/EntityNormalizer.php
+++ b/core/lib/Core/Serialization/Normalizer/EntityNormalizer.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\EntityNormalizer.
+ * Contains \Drupal\Core\Serialization\Normalizer\EntityNormalizer.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 use Drupal\Core\Entity\EntityManagerInterface;
 use Symfony\Component\Serializer\Exception\UnexpectedValueException;
diff --git a/core/modules/serialization/src/Normalizer/EntityReferenceFieldItemNormalizer.php b/core/lib/Core/Serialization/Normalizer/EntityReferenceFieldItemNormalizer.php
similarity index 89%
rename from core/modules/serialization/src/Normalizer/EntityReferenceFieldItemNormalizer.php
rename to core/lib/Core/Serialization/Normalizer/EntityReferenceFieldItemNormalizer.php
index 0fb0a0b..6219618 100644
--- a/core/modules/serialization/src/Normalizer/EntityReferenceFieldItemNormalizer.php
+++ b/core/lib/Core/Serialization/Normalizer/EntityReferenceFieldItemNormalizer.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\EntityReferenceFieldItemNormalizer.
+ * Contains \Drupal\Core\Serialization\Normalizer\EntityReferenceFieldItemNormalizer.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 use Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem;
 
diff --git a/core/modules/serialization/src/Normalizer/ListNormalizer.php b/core/lib/Core/Serialization/Normalizer/ListNormalizer.php
similarity index 89%
rename from core/modules/serialization/src/Normalizer/ListNormalizer.php
rename to core/lib/Core/Serialization/Normalizer/ListNormalizer.php
index 150229e..630d294 100644
--- a/core/modules/serialization/src/Normalizer/ListNormalizer.php
+++ b/core/lib/Core/Serialization/Normalizer/ListNormalizer.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\ListNormalizer.
+ * Contains \Drupal\Core\Serialization\Normalizer\ListNormalizer.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 /**
  * Converts list objects to arrays.
diff --git a/core/modules/serialization/src/Normalizer/MarkupNormalizer.php b/core/lib/Core/Serialization/Normalizer/MarkupNormalizer.php
similarity index 80%
rename from core/modules/serialization/src/Normalizer/MarkupNormalizer.php
rename to core/lib/Core/Serialization/Normalizer/MarkupNormalizer.php
index 761ae44..177a240 100644
--- a/core/modules/serialization/src/Normalizer/MarkupNormalizer.php
+++ b/core/lib/Core/Serialization/Normalizer/MarkupNormalizer.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\MarkupNormalizer.
+ * Contains \Drupal\Core\Serialization\Normalizer\MarkupNormalizer.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 /**
  * Normalizes MarkupInterface objects into a string.
diff --git a/core/modules/serialization/src/Normalizer/NormalizerBase.php b/core/lib/Core/Serialization/Normalizer/NormalizerBase.php
similarity index 94%
rename from core/modules/serialization/src/Normalizer/NormalizerBase.php
rename to core/lib/Core/Serialization/Normalizer/NormalizerBase.php
index ae7eaaa..441ea58 100644
--- a/core/modules/serialization/src/Normalizer/NormalizerBase.php
+++ b/core/lib/Core/Serialization/Normalizer/NormalizerBase.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\NormalizerBase.
+ * Contains \Drupal\Core\Serialization\Normalizer\NormalizerBase.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 use Symfony\Component\Serializer\Normalizer\SerializerAwareNormalizer;
diff --git a/core/modules/serialization/src/Normalizer/NullNormalizer.php b/core/lib/Core/Serialization/Normalizer/NullNormalizer.php
similarity index 82%
rename from core/modules/serialization/src/Normalizer/NullNormalizer.php
rename to core/lib/Core/Serialization/Normalizer/NullNormalizer.php
index eec36d9..d63a0e2 100644
--- a/core/modules/serialization/src/Normalizer/NullNormalizer.php
+++ b/core/lib/Core/Serialization/Normalizer/NullNormalizer.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\NullNormalizer.
+ * Contains \Drupal\Core\Serialization\Normalizer\NullNormalizer.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 /**
  * Null normalizer.
diff --git a/core/modules/serialization/src/Normalizer/TypedDataNormalizer.php b/core/lib/Core/Serialization/Normalizer/TypedDataNormalizer.php
similarity index 79%
rename from core/modules/serialization/src/Normalizer/TypedDataNormalizer.php
rename to core/lib/Core/Serialization/Normalizer/TypedDataNormalizer.php
index 2ffef44..b8c6ad3 100644
--- a/core/modules/serialization/src/Normalizer/TypedDataNormalizer.php
+++ b/core/lib/Core/Serialization/Normalizer/TypedDataNormalizer.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Normalizer\TypedDataNormalizer.
+ * Contains \Drupal\Core\Serialization\Normalizer\TypedDataNormalizer.
  */
 
-namespace Drupal\serialization\Normalizer;
+namespace Drupal\Core\Serialization\Normalizer;
 
 /**
  * Converts typed data objects to arrays.
diff --git a/core/modules/serialization/src/RegisterEntityResolversCompilerPass.php b/core/lib/Core/Serialization/RegisterEntityResolversCompilerPass.php
similarity index 94%
rename from core/modules/serialization/src/RegisterEntityResolversCompilerPass.php
rename to core/lib/Core/Serialization/RegisterEntityResolversCompilerPass.php
index 60e45eb..b773f0c 100644
--- a/core/modules/serialization/src/RegisterEntityResolversCompilerPass.php
+++ b/core/lib/Core/Serialization/RegisterEntityResolversCompilerPass.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\RegisterEntityResolversCompilerPass.
+ * Contains \Drupal\Core\Serialization\RegisterEntityResolversCompilerPass.
  */
 
-namespace Drupal\serialization;
+namespace Drupal\Core\Serialization;
 
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
diff --git a/core/modules/serialization/src/RegisterSerializationClassesCompilerPass.php b/core/lib/Core/Serialization/RegisterSerializationClassesCompilerPass.php
similarity index 95%
rename from core/modules/serialization/src/RegisterSerializationClassesCompilerPass.php
rename to core/lib/Core/Serialization/RegisterSerializationClassesCompilerPass.php
index fb87bab..28558ca 100644
--- a/core/modules/serialization/src/RegisterSerializationClassesCompilerPass.php
+++ b/core/lib/Core/Serialization/RegisterSerializationClassesCompilerPass.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\RegisterSerializationClassesCompilerPass.
+ * Contains \Drupal\Core\Serialization\RegisterSerializationClassesCompilerPass.
  */
 
-namespace Drupal\serialization;
+namespace Drupal\Core\Serialization;
 
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
diff --git a/core/modules/serialization/src/SerializationServiceProvider.php b/core/lib/Core/Serialization/SerializationServiceProvider.php
similarity index 86%
rename from core/modules/serialization/src/SerializationServiceProvider.php
rename to core/lib/Core/Serialization/SerializationServiceProvider.php
index 2e89e5c..a8bdb31 100644
--- a/core/modules/serialization/src/SerializationServiceProvider.php
+++ b/core/lib/Core/Serialization/SerializationServiceProvider.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\SerializationServiceProvider.
+ * Contains \Drupal\Core\Serialization\SerializationServiceProvider.
  */
 
-namespace Drupal\serialization;
+namespace Drupal\Core\Serialization;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\DependencyInjection\ServiceProviderInterface;
diff --git a/core/modules/serialization/src/Encoder/JsonEncoder.php b/core/lib/Drupal/Core/Serialization/Encoder/JsonEncoder.php
similarity index 88%
rename from core/modules/serialization/src/Encoder/JsonEncoder.php
rename to core/lib/Drupal/Core/Serialization/Encoder/JsonEncoder.php
index c7bedb5..a1ec64e 100644
--- a/core/modules/serialization/src/Encoder/JsonEncoder.php
+++ b/core/lib/Drupal/Core/Serialization/Encoder/JsonEncoder.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Encoder\JsonEncoder.
+ * Contains \Drupal\Core\Serialization\Encoder\JsonEncoder.
  */
 
-namespace Drupal\serialization\Encoder;
+namespace Drupal\Core\Serialization\Encoder;
 
 use Symfony\Component\Serializer\Encoder\DecoderInterface;
 use Symfony\Component\Serializer\Encoder\EncoderInterface;
diff --git a/core/modules/serialization/src/Encoder/XmlEncoder.php b/core/lib/Drupal/Core/Serialization/Encoder/XmlEncoder.php
similarity index 94%
rename from core/modules/serialization/src/Encoder/XmlEncoder.php
rename to core/lib/Drupal/Core/Serialization/Encoder/XmlEncoder.php
index 1acba41..f6c25a2 100644
--- a/core/modules/serialization/src/Encoder/XmlEncoder.php
+++ b/core/lib/Drupal/Core/Serialization/Encoder/XmlEncoder.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Encoder\XmlEncoder.
+ * Contains \Drupal\Core\Serialization\Encoder\XmlEncoder.
  */
 
-namespace Drupal\serialization\Encoder;
+namespace Drupal\Core\Serialization\Encoder;
 
 use Symfony\Component\Serializer\Encoder\EncoderInterface;
 use Symfony\Component\Serializer\Encoder\DecoderInterface;
diff --git a/core/modules/hal/src/Normalizer/EntityReferenceItemNormalizer.php b/core/modules/hal/src/Normalizer/EntityReferenceItemNormalizer.php
index 7c1943a..3e9e55f 100644
--- a/core/modules/hal/src/Normalizer/EntityReferenceItemNormalizer.php
+++ b/core/modules/hal/src/Normalizer/EntityReferenceItemNormalizer.php
@@ -9,8 +9,8 @@
 
 use Drupal\Core\Entity\FieldableEntityInterface;
 use Drupal\rest\LinkManager\LinkManagerInterface;
-use Drupal\serialization\EntityResolver\EntityResolverInterface;
-use Drupal\serialization\EntityResolver\UuidReferenceInterface;
+use Drupal\Core\Serialization\EntityResolver\EntityResolverInterface;
+use Drupal\Core\Serialization\EntityResolver\UuidReferenceInterface;
 
 /**
  * Converts the Drupal entity reference item object to HAL array structure.
@@ -34,7 +34,7 @@ class EntityReferenceItemNormalizer extends FieldItemNormalizer implements UuidR
   /**
    * The entity resolver.
    *
-   * @var \Drupal\serialization\EntityResolver\EntityResolverInterface
+   * @var \Drupal\Core\Serialization\EntityResolver\EntityResolverInterface
    */
   protected $entityResolver;
 
@@ -43,7 +43,7 @@ class EntityReferenceItemNormalizer extends FieldItemNormalizer implements UuidR
    *
    * @param \Drupal\rest\LinkManager\LinkManagerInterface $link_manager
    *   The hypermedia link manager.
-   * @param \Drupal\serialization\EntityResolver\EntityResolverInterface $entity_Resolver
+   * @param \Drupal\Core\Serialization\EntityResolver\EntityResolverInterface $entity_Resolver
    *   The entity resolver.
    */
   public function __construct(LinkManagerInterface $link_manager, EntityResolverInterface $entity_Resolver) {
diff --git a/core/modules/hal/src/Normalizer/NormalizerBase.php b/core/modules/hal/src/Normalizer/NormalizerBase.php
index 73d16fd..a1fa0ec 100644
--- a/core/modules/hal/src/Normalizer/NormalizerBase.php
+++ b/core/modules/hal/src/Normalizer/NormalizerBase.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\hal\Normalizer;
 
-use Drupal\serialization\Normalizer\NormalizerBase as SerializationNormalizerBase;
+use Drupal\Core\Serialization\Normalizer\NormalizerBase as SerializationNormalizerBase;
 use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
 
 /**
diff --git a/core/modules/hal/src/Tests/NormalizerTestBase.php b/core/modules/hal/src/Tests/NormalizerTestBase.php
index d90cde5..2ad471c 100644
--- a/core/modules/hal/src/Tests/NormalizerTestBase.php
+++ b/core/modules/hal/src/Tests/NormalizerTestBase.php
@@ -18,9 +18,9 @@
 use Drupal\rest\LinkManager\LinkManager;
 use Drupal\rest\LinkManager\RelationLinkManager;
 use Drupal\rest\LinkManager\TypeLinkManager;
-use Drupal\serialization\EntityResolver\ChainEntityResolver;
-use Drupal\serialization\EntityResolver\TargetIdResolver;
-use Drupal\serialization\EntityResolver\UuidResolver;
+use Drupal\Core\Serialization\EntityResolver\ChainEntityResolver;
+use Drupal\Core\Serialization\EntityResolver\TargetIdResolver;
+use Drupal\Core\Serialization\EntityResolver\UuidResolver;
 use Drupal\simpletest\KernelTestBase;
 use Symfony\Component\Serializer\Serializer;
 use Drupal\field\Entity\FieldStorageConfig;
diff --git a/core/modules/serialization/serialization.services.yml b/core/modules/serialization/serialization.services.yml
index c510ab1..e69de29 100644
--- a/core/modules/serialization/serialization.services.yml
+++ b/core/modules/serialization/serialization.services.yml
@@ -1,66 +0,0 @@
-services:
-  serializer:
-    class: Symfony\Component\Serializer\Serializer
-    arguments: [{  }, {  }]
-  serializer.normalizer.config_entity:
-    class: Drupal\serialization\Normalizer\ConfigEntityNormalizer
-    tags:
-      - { name: normalizer }
-    arguments: ['@entity.manager']
-  serializer.normalizer.content_entity:
-      class: Drupal\serialization\Normalizer\ContentEntityNormalizer
-      tags:
-        - { name: normalizer }
-      arguments: ['@entity.manager']
-  serializer.normalizer.entity:
-    class: Drupal\serialization\Normalizer\EntityNormalizer
-    tags:
-      - { name: normalizer }
-    arguments: ['@entity.manager']
-  serializer.normalizer.complex_data:
-    class: Drupal\serialization\Normalizer\ComplexDataNormalizer
-    tags:
-      - { name: normalizer }
-  serializer.normalizer.entity_reference_field_item:
-    class: Drupal\serialization\Normalizer\EntityReferenceFieldItemNormalizer
-    tags:
-      # Set the priority lower than the hal entity reference field item
-      # normalizer, so that we do not replace that for hal_json.
-      # @todo Find a better way for this in https://www.drupal.org/node/2575761.
-      - { name: normalizer, priority: 5 }
-  serializer.normalizer.list:
-    class: Drupal\serialization\Normalizer\ListNormalizer
-    tags:
-      - { name: normalizer }
-  serializer.normalizer.password_field_item:
-      class: Drupal\serialization\Normalizer\NullNormalizer
-      arguments: ['Drupal\Core\Field\Plugin\Field\FieldType\PasswordItem']
-      tags:
-        - { name: normalizer, priority: 20 }
-  serializer.normalizer.safe_string:
-      class: Drupal\serialization\Normalizer\MarkupNormalizer
-      tags:
-        - { name: normalizer }
-  serializer.normalizer.typed_data:
-    class: Drupal\serialization\Normalizer\TypedDataNormalizer
-    tags:
-      - { name: normalizer }
-  serializer.encoder.json:
-    class: Drupal\serialization\Encoder\JsonEncoder
-    tags:
-      - { name: encoder, format: json }
-  serializer.encoder.xml:
-    class: Drupal\serialization\Encoder\XmlEncoder
-    tags:
-      - { name: encoder, format: xml }
-  serializer.entity_resolver:
-    class: Drupal\serialization\EntityResolver\ChainEntityResolver
-  serializer.entity_resolver.uuid:
-    class: Drupal\serialization\EntityResolver\UuidResolver
-    tags:
-      - { name: entity_resolver}
-    arguments: ['@entity.manager']
-  serialization.entity_resolver.target_id:
-    class: Drupal\serialization\EntityResolver\TargetIdResolver
-    tags:
-      - { name: entity_resolver}
diff --git a/core/modules/serialization/src/EntityResolver/ChainEntityResolverInterface.php b/core/modules/serialization/src/EntityResolver/ChainEntityResolverInterface.php
index 205d1ff..54ee4c8 100644
--- a/core/modules/serialization/src/EntityResolver/ChainEntityResolverInterface.php
+++ b/core/modules/serialization/src/EntityResolver/ChainEntityResolverInterface.php
@@ -7,17 +7,16 @@
 
 namespace Drupal\serialization\EntityResolver;
 
+use Drupal\Core\Serialization\EntityResolver\ChainEntityResolverInterface as CoreChainEntityResolverInterface;
+
 /**
  * An interface for delegating a entity resolution to a chain of resolvers.
+ *
+ * @deprecated Scheduled for removal in Drupal 9.0.0. Use
+ * Drupal\Core\Serialization\EntityResolver\ChainEntityResolverInterface
+ * instead.
+ *
  */
-interface ChainEntityResolverInterface extends EntityResolverInterface {
-
-  /**
-   * Adds an entity resolver.
-   *
-   * @param \Drupal\serialization\EntityResolver\EntityResolverInterface $resolver
-   *   The entity resolver to add.
-   */
-  public function addResolver(EntityResolverInterface $resolver);
+interface ChainEntityResolverInterface extends CoreChainEntityResolverInterface {
 
 }
diff --git a/core/modules/serialization/src/EntityResolver/EntityResolverInterface.php b/core/modules/serialization/src/EntityResolver/EntityResolverInterface.php
index 883bb8b..54d2e04 100644
--- a/core/modules/serialization/src/EntityResolver/EntityResolverInterface.php
+++ b/core/modules/serialization/src/EntityResolver/EntityResolverInterface.php
@@ -7,37 +7,13 @@
 
 namespace Drupal\serialization\EntityResolver;
 
-use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+use Drupal\Core\Serialization\EntityResolver\EntityResolverInterface as CoreEntityResolverInterface;;
 
-interface EntityResolverInterface {
-
-  /**
-   * Returns the local ID of an entity referenced by serialized data.
-   *
-   * Drupal entities are loaded by and internally referenced by a local ID.
-   * Because different websites can use the same local ID to refer to different
-   * entities (e.g., node "1" can be a different node on foo.com and bar.com, or
-   * on example.com and staging.example.com), it is generally unsuitable for use
-   * in hypermedia data exchanges. Instead, UUIDs, URIs, or other globally
-   * unique IDs are preferred.
-   *
-   * This function takes a $data array representing partially deserialized data
-   * for an entity reference, and resolves it to a local entity ID. For example,
-   * depending on the data specification being used, $data might contain a
-   * 'uuid' key, a 'uri' key, a 'href' key, or some other data identifying the
-   * entity, and it is up to the implementor of this interface to resolve that
-   * appropriately for the specification being used.
-   *
-   * @param \Symfony\Component\Serializer\Normalizer\NormalizerInterface $normalizer
-   *   The Normalizer which is handling the data.
-   * @param array $data
-   *   The data passed into the calling Normalizer.
-   * @param string $entity_type
-   *   The type of entity being resolved; e.g., 'node' or 'user'.
-   *
-   * @return string|null
-   *   Returns the local entity ID, if found. Otherwise, returns NULL.
-   */
-  public function resolve(NormalizerInterface $normalizer, $data, $entity_type);
+/**
+ * @deprecated Scheduled for removal in Drupal 9.0.0. Use
+ * Drupal\Core\Serialization\EntityResolver\EntityResolverInterface
+ * instead.
+ */
+interface EntityResolverInterface extends CoreEntityResolverInterface {
 
 }
diff --git a/core/modules/serialization/src/EntityResolver/UuidReferenceInterface.php b/core/modules/serialization/src/EntityResolver/UuidReferenceInterface.php
index 632eef4..116b8d1 100644
--- a/core/modules/serialization/src/EntityResolver/UuidReferenceInterface.php
+++ b/core/modules/serialization/src/EntityResolver/UuidReferenceInterface.php
@@ -7,22 +7,15 @@
 
 namespace Drupal\serialization\EntityResolver;
 
-use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+use Drupal\Core\Serialization\EntityResolver\UuidReferenceInterface as CoreUuidReferenceInterface;
 
 /**
  * Interface for extracting UUID from entity reference data when denormalizing.
+ *
+ * @deprecated Scheduled for removal in Drupal 9.0.0. Use
+ * Drupal\Core\Serialization\EntityResolver\UuidReferenceInterface
+ * instead.
  */
-interface UuidReferenceInterface extends NormalizerInterface {
-
-  /**
-   * Get the uuid from the data array.
-   *
-   * @param array $data
-   *   The data, as was passed into the Normalizer.
-   *
-   * @return string
-   *   A UUID.
-   */
-  public function getUuid($data);
+interface UuidReferenceInterface extends CoreUuidReferenceInterface {
 
 }
diff --git a/core/modules/serialization/tests/src/Unit/Encoder/JsonEncoderTest.php b/core/modules/serialization/tests/src/Unit/Encoder/JsonEncoderTest.php
index 2ba8680..3eba195 100644
--- a/core/modules/serialization/tests/src/Unit/Encoder/JsonEncoderTest.php
+++ b/core/modules/serialization/tests/src/Unit/Encoder/JsonEncoderTest.php
@@ -7,11 +7,11 @@
 
 namespace Drupal\Tests\serialization\Unit\Encoder;
 
-use Drupal\serialization\Encoder\JsonEncoder;
+use Drupal\Core\Serialization\Encoder\JsonEncoder;
 use Drupal\Tests\UnitTestCase;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Encoder\JsonEncoder
+ * @coversDefaultClass \Drupal\Core\Serialization\Encoder\JsonEncoder
  * @group serialization
  */
 class JsonEncoderTest extends UnitTestCase {
diff --git a/core/modules/serialization/tests/src/Unit/Encoder/XmlEncoderTest.php b/core/modules/serialization/tests/src/Unit/Encoder/XmlEncoderTest.php
index b814154..b14ff4f 100644
--- a/core/modules/serialization/tests/src/Unit/Encoder/XmlEncoderTest.php
+++ b/core/modules/serialization/tests/src/Unit/Encoder/XmlEncoderTest.php
@@ -7,11 +7,11 @@
 
 namespace Drupal\Tests\serialization\Unit\Encoder;
 
-use Drupal\serialization\Encoder\XmlEncoder;
+use Drupal\Core\Serialization\Encoder\XmlEncoder;
 use Drupal\Tests\UnitTestCase;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Encoder\XmlEncoder
+ * @coversDefaultClass \Drupal\Core\Serialization\Encoder\XmlEncoder
  * @group serialization
  */
 class XmlEncoderTest extends UnitTestCase {
@@ -19,7 +19,7 @@ class XmlEncoderTest extends UnitTestCase {
   /**
    * The XmlEncoder instance.
    *
-   * @var \Drupal\serialization\Encoder\XmlEncoder
+   * @var \Drupal\Core\Serialization\Encoder\XmlEncoder
    */
   protected $encoder;
 
diff --git a/core/modules/serialization/tests/src/Unit/EntityResolver/ChainEntityResolverTest.php b/core/modules/serialization/tests/src/Unit/EntityResolver/ChainEntityResolverTest.php
index 22cffac..9de8ca5 100644
--- a/core/modules/serialization/tests/src/Unit/EntityResolver/ChainEntityResolverTest.php
+++ b/core/modules/serialization/tests/src/Unit/EntityResolver/ChainEntityResolverTest.php
@@ -8,10 +8,10 @@
 namespace Drupal\Tests\serialization\Unit\EntityResolver;
 
 use Drupal\Tests\UnitTestCase;
-use Drupal\serialization\EntityResolver\ChainEntityResolver;
+use Drupal\Core\Serialization\EntityResolver\ChainEntityResolver;
 
 /**
- * @coversDefaultClass \Drupal\serialization\EntityResolver\ChainEntityResolver
+ * @coversDefaultClass \Drupal\Core\Serialization\EntityResolver\ChainEntityResolver
  * @group serialization
  */
 class ChainEntityResolverTest extends UnitTestCase {
@@ -136,11 +136,11 @@ public function testResolverWithResolvedToZero() {
    * @param bool $called
    *   Whether or not the resolve method is expected to be called.
    *
-   * @return \Drupal\serialization\EntityResolver\EntityResolverInterface|\PHPUnit_Framework_MockObject_MockObject
+   * @return \Drupal\Core\Serialization\EntityResolver\EntityResolverInterface|\PHPUnit_Framework_MockObject_MockObject
    *   The mocked entity resolver.
    */
   protected function createEntityResolverMock($return = NULL, $called = TRUE) {
-    $mock = $this->getMock('Drupal\serialization\EntityResolver\EntityResolverInterface');
+    $mock = $this->getMock('Drupal\Core\Serialization\EntityResolver\EntityResolverInterface');
 
     if ($called) {
       $mock->expects($this->once())
diff --git a/core/modules/serialization/tests/src/Unit/EntityResolver/UuidResolverTest.php b/core/modules/serialization/tests/src/Unit/EntityResolver/UuidResolverTest.php
index 940c1bdc..abe28e3 100644
--- a/core/modules/serialization/tests/src/Unit/EntityResolver/UuidResolverTest.php
+++ b/core/modules/serialization/tests/src/Unit/EntityResolver/UuidResolverTest.php
@@ -8,10 +8,10 @@
 namespace Drupal\Tests\serialization\Unit\EntityResolver;
 
 use Drupal\Tests\UnitTestCase;
-use Drupal\serialization\EntityResolver\UuidResolver;
+use Drupal\Core\Serialization\EntityResolver\UuidResolver;
 
 /**
- * @coversDefaultClass \Drupal\serialization\EntityResolver\UuidResolver
+ * @coversDefaultClass \Drupal\Core\Serialization\EntityResolver\UuidResolver
  * @group serialization
  */
 class UuidResolverTest extends UnitTestCase {
@@ -19,7 +19,7 @@ class UuidResolverTest extends UnitTestCase {
   /**
    * The UuidResolver instance.
    *
-   * @var \Drupal\serialization\EntityResolver\UuidResolver
+   * @var \Drupal\Core\Serialization\EntityResolver\UuidResolver
    */
   protected $resolver;
 
@@ -59,7 +59,7 @@ public function testResolveNoUuid() {
     $this->entityManager->expects($this->never())
       ->method('loadEntityByUuid');
 
-    $normalizer = $this->getMock('Drupal\serialization\EntityResolver\UuidReferenceInterface');
+    $normalizer = $this->getMock('Drupal\Core\Serialization\EntityResolver\UuidReferenceInterface');
     $normalizer->expects($this->once())
       ->method('getUuid')
       ->with(array())
@@ -78,7 +78,7 @@ public function testResolveNoEntity() {
       ->with('test_type')
       ->will($this->returnValue(NULL));
 
-    $normalizer = $this->getMock('Drupal\serialization\EntityResolver\UuidReferenceInterface');
+    $normalizer = $this->getMock('Drupal\Core\Serialization\EntityResolver\UuidReferenceInterface');
     $normalizer->expects($this->once())
       ->method('getUuid')
       ->with(array())
@@ -103,7 +103,7 @@ public function testResolveWithEntity() {
       ->with('test_type', $uuid)
       ->will($this->returnValue($entity));
 
-    $normalizer = $this->getMock('Drupal\serialization\EntityResolver\UuidReferenceInterface');
+    $normalizer = $this->getMock('Drupal\Core\Serialization\EntityResolver\UuidReferenceInterface');
     $normalizer->expects($this->once())
       ->method('getUuid')
       ->with(array())
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/ComplexDataNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/ComplexDataNormalizerTest.php
index dc14d6f..99e0970 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/ComplexDataNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/ComplexDataNormalizerTest.php
@@ -7,14 +7,14 @@
 
 namespace Drupal\Tests\serialization\Unit\Normalizer;
 
+use Drupal\Core\Serialization\Normalizer\ComplexDataNormalizer;
 use Drupal\Core\TypedData\ComplexDataInterface;
 use Drupal\Core\TypedData\TraversableTypedDataInterface;
-use Drupal\serialization\Normalizer\ComplexDataNormalizer;
 use Drupal\Tests\UnitTestCase;
 use Symfony\Component\Serializer\Serializer;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Normalizer\ComplexDataNormalizer
+ * @coversDefaultClass \Drupal\Core\Serialization\Normalizer\ComplexDataNormalizer
  * @group serialization
  */
 class ComplexDataNormalizerTest extends UnitTestCase {
@@ -29,7 +29,7 @@ class ComplexDataNormalizerTest extends UnitTestCase {
   /**
    * The Complex data normalizer under test.
    *
-   * @var \Drupal\serialization\Normalizer\ComplexDataNormalizer
+   * @var \Drupal\Core\Serialization\Normalizer\ComplexDataNormalizer
    */
   protected $normalizer;
 
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/ConfigEntityNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/ConfigEntityNormalizerTest.php
index 466caf5..e046897 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/ConfigEntityNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/ConfigEntityNormalizerTest.php
@@ -7,11 +7,11 @@
 
 namespace Drupal\Tests\serialization\Unit\Normalizer;
 
-use Drupal\serialization\Normalizer\ConfigEntityNormalizer;
+use Drupal\Core\Serialization\Normalizer\ConfigEntityNormalizer;
 use Drupal\Tests\UnitTestCase;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Normalizer\ConfigEntityNormalizer
+ * @coversDefaultClass \Drupal\Core\Serialization\Normalizer\ConfigEntityNormalizer
  * @group serialization
  */
 class ConfigEntityNormalizerTest extends UnitTestCase {
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/ContentEntityNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/ContentEntityNormalizerTest.php
index d9ca3e8..f7ac30b 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/ContentEntityNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/ContentEntityNormalizerTest.php
@@ -7,11 +7,11 @@
 
 namespace Drupal\Tests\serialization\Unit\Normalizer;
 
-use Drupal\serialization\Normalizer\ContentEntityNormalizer;
+use Drupal\Core\Serialization\Normalizer\ContentEntityNormalizer;
 use Drupal\Tests\UnitTestCase;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Normalizer\ContentEntityNormalizer
+ * @coversDefaultClass \Drupal\Core\Serialization\Normalizer\ContentEntityNormalizer
  * @group serialization
  */
 class ContentEntityNormalizerTest extends UnitTestCase {
@@ -33,7 +33,7 @@ class ContentEntityNormalizerTest extends UnitTestCase {
   /**
    * The normalizer under test.
    *
-   * @var \Drupal\serialization\Normalizer\ContentEntityNormalizer
+   * @var \Drupal\Core\Serialization\Normalizer\ContentEntityNormalizer
    */
   protected $contentEntityNormalizer;
 
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/EntityNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/EntityNormalizerTest.php
index 0cd5983..7fd416c 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/EntityNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/EntityNormalizerTest.php
@@ -7,11 +7,11 @@
 
 namespace Drupal\Tests\serialization\Unit\Normalizer;
 
-use Drupal\serialization\Normalizer\EntityNormalizer;
+use Drupal\Core\Serialization\Normalizer\EntityNormalizer;
 use Drupal\Tests\UnitTestCase;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Normalizer\EntityNormalizer
+ * @coversDefaultClass \Drupal\Core\Serialization\Normalizer\EntityNormalizer
  * @group serialization
  */
 class EntityNormalizerTest extends UnitTestCase {
@@ -33,7 +33,7 @@ class EntityNormalizerTest extends UnitTestCase {
   /**
    * The entity normalizer.
    *
-   * @var \Drupal\serialization\Normalizer\EntityNormalizer
+   * @var \Drupal\Core\Serialization\Normalizer\EntityNormalizer
    */
   protected $entityNormalizer;
 
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/EntityReferenceFieldItemNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/EntityReferenceFieldItemNormalizerTest.php
index 04cfa16..1a85811 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/EntityReferenceFieldItemNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/EntityReferenceFieldItemNormalizerTest.php
@@ -10,13 +10,13 @@
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\TypedData\TypedDataInterface;
 use Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem;
-use Drupal\serialization\Normalizer\EntityReferenceFieldItemNormalizer;
+use Drupal\Core\Serialization\Normalizer\EntityReferenceFieldItemNormalizer;
 use Drupal\Tests\UnitTestCase;
 use Prophecy\Argument;
 use Symfony\Component\Serializer\Serializer;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Normalizer\EntityReferenceFieldItemNormalizer
+ * @coversDefaultClass \Drupal\Core\Serialization\Normalizer\EntityReferenceFieldItemNormalizer
  * @group serialization
  */
 class EntityReferenceFieldItemNormalizerTest extends UnitTestCase {
@@ -31,7 +31,7 @@ class EntityReferenceFieldItemNormalizerTest extends UnitTestCase {
   /**
    * The normalizer under test.
    *
-   * @var \Drupal\serialization\Normalizer\EntityReferenceFieldItemNormalizer
+   * @var \Drupal\Core\Serialization\Normalizer\EntityReferenceFieldItemNormalizer
    */
   protected $normalizer;
 
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/ListNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/ListNormalizerTest.php
index e5ea66b..5461b9e 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/ListNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/ListNormalizerTest.php
@@ -9,11 +9,11 @@
 
 use Drupal\Core\TypedData\DataDefinition;
 use Drupal\Tests\UnitTestCase;
-use Drupal\serialization\Normalizer\ListNormalizer;
+use Drupal\Core\Serialization\Normalizer\ListNormalizer;
 use Drupal\Core\TypedData\Plugin\DataType\ItemList;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Normalizer\ListNormalizer
+ * @coversDefaultClass \Drupal\Core\Serialization\Normalizer\ListNormalizer
  * @group serialization
  */
 class ListNormalizerTest extends UnitTestCase {
@@ -21,7 +21,7 @@ class ListNormalizerTest extends UnitTestCase {
   /**
    * The ListNormalizer instance.
    *
-   * @var \Drupal\serialization\Normalizer\ListNormalizer
+   * @var \Drupal\Core\Serialization\Normalizer\ListNormalizer
    */
   protected $normalizer;
 
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php
index e77882a..853e57b 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php
@@ -8,10 +8,10 @@
 namespace Drupal\Tests\serialization\Unit\Normalizer;
 
 use Drupal\Tests\UnitTestCase;
-use Drupal\serialization\Normalizer\NormalizerBase;
+use Drupal\Core\Serialization\Normalizer\NormalizerBase;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Normalizer\NormalizerBase
+ * @coversDefaultClass \Drupal\Core\Serialization\Normalizer\NormalizerBase
  * @group serialization
  */
 class NormalizerBaseTest extends UnitTestCase {
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/NullNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/NullNormalizerTest.php
index 28c7af7..63aa4d5 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/NullNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/NullNormalizerTest.php
@@ -7,11 +7,11 @@
 
 namespace Drupal\Tests\serialization\Unit\Normalizer;
 
-use Drupal\serialization\Normalizer\NullNormalizer;
+use Drupal\Core\Serialization\Normalizer\NullNormalizer;
 use Drupal\Tests\UnitTestCase;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Normalizer\NullNormalizer
+ * @coversDefaultClass \Drupal\Core\Serialization\Normalizer\NullNormalizer
  * @group serialization
  */
 class NullNormalizerTest extends UnitTestCase {
@@ -19,7 +19,7 @@ class NullNormalizerTest extends UnitTestCase {
   /**
    * The NullNormalizer instance.
    *
-   * @var \Drupal\serialization\Normalizer\NullNormalizer
+   * @var \Drupal\Core\Serialization\Normalizer\NullNormalizer
    */
   protected $normalizer;
 
diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/TypedDataNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/TypedDataNormalizerTest.php
index 1b9c101..f14a0bf 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/TypedDataNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/TypedDataNormalizerTest.php
@@ -8,10 +8,10 @@
 namespace Drupal\Tests\serialization\Unit\Normalizer;
 
 use Drupal\Tests\UnitTestCase;
-use Drupal\serialization\Normalizer\TypedDataNormalizer;
+use Drupal\Core\Serialization\Normalizer\TypedDataNormalizer;
 
 /**
- * @coversDefaultClass \Drupal\serialization\Normalizer\TypedDataNormalizer
+ * @coversDefaultClass \Drupal\Core\Serialization\Normalizer\TypedDataNormalizer
  * @group serialization
  */
 class TypedDataNormalizerTest extends UnitTestCase {
@@ -19,7 +19,7 @@ class TypedDataNormalizerTest extends UnitTestCase {
   /**
    * The TypedDataNormalizer instance.
    *
-   * @var \Drupal\serialization\Normalizer\TypedDataNormalizer
+   * @var \Drupal\Core\Serialization\Normalizer\TypedDataNormalizer
    */
   protected $normalizer;