jsonapi.services.yml                               | 21 +++++++++---
 src/Controller/RequestHandler.php                  |  2 +-
 .../RegisterNormalizerClassesCompilerPass.php      | 37 ++++++++++++++++++++++
 src/JsonapiServiceProvider.php                     | 11 ++++++-
 .../JsonApiDocumentTopLevelNormalizerTest.php      |  4 +--
 5 files changed, 66 insertions(+), 9 deletions(-)

diff --git a/jsonapi.services.yml b/jsonapi.services.yml
index c111a8e..0b47f98 100644
--- a/jsonapi.services.yml
+++ b/jsonapi.services.yml
@@ -56,10 +56,6 @@ services:
     arguments: ['@jsonapi.link_manager', '@entity_field.manager', '@plugin.manager.field.field_type', '@jsonapi.resource_type.repository', '@entity.repository']
     tags:
       - { name: normalizer, priority: 31 }
-  serializer.encoder.jsonapi:
-    class: Drupal\jsonapi\Encoder\JsonEncoder
-    tags:
-      - { name: encoder, priority: 21, format: 'api_json' }
   jsonapi.resource_type.repository:
     class: Drupal\jsonapi\ResourceType\ResourceTypeRepository
     arguments: ['@entity_type.manager', '@entity_type.bundle.info']
@@ -100,4 +96,19 @@ services:
     class: Drupal\jsonapi\EventSubscriber\DefaultExceptionSubscriber
     tags:
       - { name: event_subscriber }
-    arguments: ['@serializer', '%serializer.formats%']
+    arguments: ['@jsonapi.serializer', '%serializer.formats%']
+
+  # We want the 'api_json' format to not be supported in the REST module, so we cannot register its encoder with the
+  # Serialization module. Hence we have an encoder without the 'encoder' tag and 'format' property. But that also means
+  # we cannot reuse the @serializer service. So we define our own serializer service. But we still do want to reuse the
+  # generic normalizers from the Serialization module. So we inject all normalizers just like the default @serializer
+  # service does. Only appropriate normalizers are called thanks to the supportsNormalization() API method.
+  # @see \Drupal\jsonapi\DependencyInjection\Compiler\RegisterNormalizerClassesCompilerPass
+  # @see \Drupal\jsonapi\JsonapiServiceProvider::register()
+  # @see \Drupal\Tests\jsonapi\Functional\RestJsonApiUnsupported
+  # @see \Symfony\Component\Serializer\Normalizer\NormalizerInterface::supportsNormalization
+  jsonapi.serializer:
+    class: Symfony\Component\Serializer\Serializer
+    arguments: [{  }, ['@serializer.encoder.jsonapi']]
+  serializer.encoder.jsonapi:
+    class: Drupal\jsonapi\Encoder\JsonEncoder
diff --git a/src/Controller/RequestHandler.php b/src/Controller/RequestHandler.php
index 4c4fb5a..410529d 100644
--- a/src/Controller/RequestHandler.php
+++ b/src/Controller/RequestHandler.php
@@ -54,7 +54,7 @@ class RequestHandler implements ContainerAwareInterface, ContainerInjectionInter
 
     // Deserialize incoming data if available.
     /* @var \Symfony\Component\Serializer\SerializerInterface $serializer */
-    $serializer = $this->container->get('serializer');
+    $serializer = $this->container->get('jsonapi.serializer');
     /* @var \Drupal\jsonapi\Context\CurrentContext $current_context */
     $current_context = $this->container->get('jsonapi.current_context');
     $unserialized = $this->deserializeBody($request, $serializer, $route->getOption('serialization_class'), $current_context);
diff --git a/src/DependencyInjection/Compiler/RegisterNormalizerClassesCompilerPass.php b/src/DependencyInjection/Compiler/RegisterNormalizerClassesCompilerPass.php
new file mode 100644
index 0000000..32b5394
--- /dev/null
+++ b/src/DependencyInjection/Compiler/RegisterNormalizerClassesCompilerPass.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Drupal\jsonapi\DependencyInjection\Compiler;
+
+use Drupal\serialization\RegisterSerializationClassesCompilerPass;
+use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+/**
+ * Adds services tagged 'normalizer' to the JSON API Serializer.
+ *
+ * @see \Drupal\serialization\RegisterSerializationClassesCompilerPass
+ */
+class RegisterNormalizerClassesCompilerPass extends RegisterSerializationClassesCompilerPass  {
+
+  /**
+   * Adds services to the Serializer.
+   *
+   * @param \Symfony\Component\DependencyInjection\ContainerBuilder $container
+   *   The container to process.
+   */
+  public function process(ContainerBuilder $container) {
+    $definition = $container->getDefinition('jsonapi.serializer');
+
+    // Retrieve registered Normalizers from the container.
+    foreach ($container->findTaggedServiceIds('normalizer') as $id => $attributes) {
+      $priority = isset($attributes[0]['priority']) ? $attributes[0]['priority'] : 0;
+      $normalizers[$priority][] = new Reference($id);
+    }
+
+    // Add the registered Normalizers to the JSON API Serializer.
+    if (!empty($normalizers)) {
+      $definition->replaceArgument(0, $this->sort($normalizers));
+    }
+  }
+
+}
diff --git a/src/JsonapiServiceProvider.php b/src/JsonapiServiceProvider.php
index b5f9ea9..349af52 100644
--- a/src/JsonapiServiceProvider.php
+++ b/src/JsonapiServiceProvider.php
@@ -4,13 +4,15 @@ namespace Drupal\jsonapi;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\DependencyInjection\ServiceModifierInterface;
+use Drupal\Core\DependencyInjection\ServiceProviderInterface;
+use Drupal\jsonapi\DependencyInjection\Compiler\RegisterNormalizerClassesCompilerPass;
 
 /**
  * Adds api_json as known format.
  *
  * @internal
  */
-class JsonapiServiceProvider implements ServiceModifierInterface {
+class JsonapiServiceProvider implements ServiceModifierInterface, ServiceProviderInterface  {
 
   /**
    * {@inheritdoc}
@@ -28,4 +30,11 @@ class JsonapiServiceProvider implements ServiceModifierInterface {
     }
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function register(ContainerBuilder $container) {
+    $container->addCompilerPass(new RegisterNormalizerClassesCompilerPass());
+  }
+
 }
diff --git a/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php b/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php
index 1238874..16dd793 100644
--- a/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php
+++ b/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php
@@ -339,7 +339,7 @@ class JsonApiDocumentTopLevelNormalizerTest extends JsonapiKernelTestBase {
     $response = new ResourceResponse();
     $normalized = $this
       ->container
-      ->get('serializer')
+      ->get('jsonapi.serializer')
       ->serialize(
         new BadRequestHttpException('Lorem'),
         'api_json',
@@ -572,7 +572,7 @@ class JsonApiDocumentTopLevelNormalizerTest extends JsonapiKernelTestBase {
     $request_stack = $this->container->get('request_stack');
     $request_stack->push($request);
     $this->container->set('request_stack', $request_stack);
-    $this->container->get('serializer');
+    $this->container->get('jsonapi.serializer');
 
     return [$request, $resource_type];
   }