diff --git a/features/main/object_primary_key.feature b/features/main/object_primary_key.feature
new file mode 100644
index 00000000000..03445389982
--- /dev/null
+++ b/features/main/object_primary_key.feature
@@ -0,0 +1,24 @@
+Feature: Planning handling
+  In order to use an object as primary key
+  As a developer
+  I should be able serialize types with object primary key.
+
+  @createSchema
+  @dropSchema
+  Scenario: Get a resource containing a raw object
+    When  I send a "GET" request to "/object_primary_keys/2017-01-30"
+    Then print last JSON response
+  Scenario: Get a resource
+    When I send a "GET" request to "/object_primary_keys/2017-01-30"
+    Then the response status code should be 200
+    And the response should be in JSON
+    And the header "Content-Type" should be equal to "application/ld+json; charset=utf-8"
+    And the JSON should be equal to:
+    """
+    {
+      "@context": "/contexts/ObjectPrimaryKey",
+      "@id": "/object_primary_keys/2017-01-30",
+      "@type": "ObjectPrimaryKey",
+      "date": "2017-01-30"
+    }
+    """
diff --git a/tests/Fixtures/TestBundle/DataProvider/ObjectPrimaryKeyItemDataProvider.php b/tests/Fixtures/TestBundle/DataProvider/ObjectPrimaryKeyItemDataProvider.php
new file mode 100644
index 00000000000..f8d3660eed9
--- /dev/null
+++ b/tests/Fixtures/TestBundle/DataProvider/ObjectPrimaryKeyItemDataProvider.php
@@ -0,0 +1,38 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <dunglas@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace ApiPlatform\Core\Tests\Fixtures\TestBundle\DataProvider;
+
+use ApiPlatform\Core\DataProvider\ItemDataProviderInterface;
+use ApiPlatform\Core\Exception\ResourceClassNotSupportedException;
+use ApiPlatform\Core\Tests\Fixtures\TestBundle\Entity\ObjectPrimaryKey;
+use DateTime;
+
+/**
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+class ObjectPrimaryKeyItemDataProvider implements ItemDataProviderInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function getItem(string $resourceClass, $id, string $operationName = null, array $context = [])
+    {
+        if (ObjectPrimaryKey::class !== $resourceClass) {
+            throw new ResourceClassNotSupportedException();
+        }
+
+        $planning = new ObjectPrimaryKey();
+        $planning->setDate(new DateTime($id));
+
+        return $planning;
+    }
+}
diff --git a/tests/Fixtures/TestBundle/Entity/ObjectPrimaryKey.php b/tests/Fixtures/TestBundle/Entity/ObjectPrimaryKey.php
new file mode 100644
index 00000000000..192772385cb
--- /dev/null
+++ b/tests/Fixtures/TestBundle/Entity/ObjectPrimaryKey.php
@@ -0,0 +1,45 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <dunglas@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace ApiPlatform\Core\Tests\Fixtures\TestBundle\Entity;
+
+use ApiPlatform\Core\Annotation\ApiResource;
+use DateTime;
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * Planning.
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ *
+ * @ApiResource
+ * @ORM\Entity
+ */
+class ObjectPrimaryKey
+{
+    /**
+     * @var DateTime
+     *
+     * @ORM\Column(type="date")
+     * @ORM\Id
+     */
+    private $date;
+
+    public function getDate(): DateTime
+    {
+        return $this->date;
+    }
+
+    public function setDate(DateTime $date)
+    {
+        $this->date = $date;
+    }
+}
diff --git a/tests/Fixtures/app/config/config.yml b/tests/Fixtures/app/config/config.yml
index b29382a6164..712d99639cd 100644
--- a/tests/Fixtures/app/config/config.yml
+++ b/tests/Fixtures/app/config/config.yml
@@ -69,6 +69,10 @@ nelmio_api_doc:
                 json:       'application/json'
 
 services:
+    object_primary_key.item_data_provider:
+        class: 'ApiPlatform\Core\Tests\Fixtures\TestBundle\DataProvider\ObjectPrimaryKeyItemDataProvider'
+        tags:
+            -  { name: 'api_platform.item_data_provider' }
     app.user_manager:
         class: 'ApiPlatform\Core\Tests\Fixtures\TestBundle\Manager\UserManager'
         arguments: