diff --git a/tests/src/Unit/EventSubscriber/ResourceResponseSubscriberTest.php b/tests/src/Unit/EventSubscriber/ResourceResponseSubscriberTest.php
index 06da13c..7fd8dd3 100644
--- a/tests/src/Unit/EventSubscriber/ResourceResponseSubscriberTest.php
+++ b/tests/src/Unit/EventSubscriber/ResourceResponseSubscriberTest.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\Tests\jsonapi\Unit\EventSubscriber;
 
+use Drupal\Core\Extension\Extension;
+use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Render\RendererInterface;
 use Drupal\jsonapi\EventSubscriber\ResourceResponseSubscriber;
 use Drupal\rest\ResourceResponse;
@@ -15,6 +17,8 @@ use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\Routing\Route;
 use Symfony\Component\Serializer\Serializer;
 
+define('DRUPAL_ROOT', dirname(dirname(dirname(dirname(dirname(__DIR__))))));
+
 /**
  * @coversDefaultClass \Drupal\jsonapi\EventSubscriber\ResourceResponseSubscriber
  * @group jsonapi
@@ -37,10 +41,17 @@ class ResourceResponseSubscriberTest extends UnitTestCase {
       $this->fail('The JSON Schema validator is missing. You can install it with `composer require justinrainbow/json-schema`.');
     }
 
+    $module_handler = $this->prophesize(ModuleHandlerInterface::class);
+    $module = $this->prophesize(Extension::class);
+    $module->getPath()->willReturn('jsonapi');
+    $module_handler->getModule('jsonapi')->willReturn(
+      $module->reveal()
+    );
     $subscriber = new ResourceResponseSubscriber(
       new Serializer([], [new JsonSchemaEncoder()]),
       $this->prophesize(RendererInterface::class)->reveal(),
-      $this->prophesize(LoggerInterface::class)->reveal()
+      $this->prophesize(LoggerInterface::class)->reveal(),
+      $module_handler->reveal()
     );
     $subscriber->setValidator();
     $this->subscriber = $subscriber;