diff --git a/block_field.services.yml b/block_field.services.yml
index 2b87c49..e953d1f 100755
--- a/block_field.services.yml
+++ b/block_field.services.yml
@@ -2,10 +2,3 @@ services:
   block_field.manager:
     class: Drupal\block_field\BlockFieldManager
     arguments: ['@plugin.manager.block']
-  serializer.normalizer.block_field_item:
-    class: Drupal\block_field\Normalizer\BlockFieldItemNormalizer
-    arguments: ['@hal.link_manager', '@serializer.entity_resolver']
-    # The priority must be higher than that of
-    # serializer.normalizer.field_item.hal in hal.services.yml.
-    tags:
-      - { name: normalizer, priority: 20}
diff --git a/src/BlockFieldServiceProvider.php b/src/BlockFieldServiceProvider.php
new file mode 100644
index 0000000..3e3a9c8
--- /dev/null
+++ b/src/BlockFieldServiceProvider.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Drupal\block_field;
+
+use Drupal\block_field\Normalizer\BlockFieldItemNormalizer;
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Core\DependencyInjection\ServiceProviderBase;
+use Symfony\Component\DependencyInjection\Definition;
+use Symfony\Component\DependencyInjection\Reference;
+
+/**
+ * Service Provider for block_field module.
+ */
+class BlockFieldServiceProvider extends ServiceProviderBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function alter(ContainerBuilder $container) {
+    $modules = $container->getParameter('container.modules');
+    if (isset($modules['hal'])) {
+      // In case Hal module is enabled, add a normalizer for block field items.
+      $service_definition = new Definition(BlockFieldItemNormalizer::class, [
+        new Reference('hal.link_manager'),
+        new Reference('serializer.entity_resolver'),
+      ]);
+      // The priority must be higher than that of
+      // serializer.normalizer.field_item.hal in hal.services.yml.
+      $service_definition->addTag('normalizer', ['priority' => 20]);
+      $container->setDefinition('serializer.normalizer.block_field_item', $service_definition);
+    }
+  }
+
+}