diff --git a/src/DataProvider/CourseCollectionDataProvider.php b/src/DataProvider/CourseCollectionDataProvider.php
index 5b9de4986df0685e22547db69fcef0883e29c4cc..421d1fd5f45f115948c7aa2f6ff2015bc57b06c9 100644
--- a/src/DataProvider/CourseCollectionDataProvider.php
+++ b/src/DataProvider/CourseCollectionDataProvider.php
@@ -48,7 +48,9 @@ final class CourseCollectionDataProvider extends AbstractController implements C
             if (!empty($personId)) {
                 $coursesByPerson = $this->courseProvider->getCoursesByPerson($personId, $options);
                 if (!empty($organizationId)) {
-                    $courses = array_uintersect($courses, $coursesByPerson, compareCourses);
+                    $courses = array_uintersect($courses, $coursesByPerson,
+                        'Dbp\Relay\BaseCourseBundle\DataProvider\CourseCollectionDataProvider::compareCourses');
+                    $courses = array_values($courses);
                 } else {
                     $courses = $coursesByPerson;
                 }
@@ -70,11 +72,11 @@ final class CourseCollectionDataProvider extends AbstractController implements C
         return new ArrayFullPaginator($courses, $page, $perPage);
     }
 
-    private static function compareCourses(Course $a, Course $b): int
+    public static function compareCourses(Course $a, Course $b): int
     {
         if ($a->getIdentifier() > $b->getIdentifier()) {
             return 1;
-        } else if ($a->getIdentifier() === $b->getIdentifier()) {
+        } elseif ($a->getIdentifier() === $b->getIdentifier()) {
             return 0;
         } else {
             return -1;
diff --git a/src/Entity/Course.php b/src/Entity/Course.php
index c40fac7452d6a87170890b2e6b2d45e3ef0a7fbd..7b419e8953663854120415525ab264ca431ec607 100644
--- a/src/Entity/Course.php
+++ b/src/Entity/Course.php
@@ -5,8 +5,6 @@ declare(strict_types=1);
 namespace Dbp\Relay\BaseCourseBundle\Entity;
 
 use ApiPlatform\Core\Annotation\ApiResource;
-use Dbp\Relay\BaseCourseBundle\Controller\GetCoursesByOrganization;
-use Dbp\Relay\BaseCourseBundle\Controller\GetCoursesByPerson;
 use Symfony\Component\Serializer\Annotation\Groups;
 
 /**