diff --git a/src/Bundle/ChillPersonBundle/Tests/Entity/AccompanyingPeriod/AccompanyingPeriodWorkTest.php b/src/Bundle/ChillPersonBundle/Tests/Entity/AccompanyingPeriod/AccompanyingPeriodWorkTest.php
index 45c2ed680..b0e82c99c 100644
--- a/src/Bundle/ChillPersonBundle/Tests/Entity/AccompanyingPeriod/AccompanyingPeriodWorkTest.php
+++ b/src/Bundle/ChillPersonBundle/Tests/Entity/AccompanyingPeriod/AccompanyingPeriodWorkTest.php
@@ -55,6 +55,8 @@ class AccompanyingPeriodWorkTest extends TestCase
         self::assertNotContains($userA, $work->getReferrers());
         self::assertNotContains($userB, $work->getReferrers());
         self::assertContains($userC, $work->getReferrers());
+
+        self::assertTrue(array_is_list($work->getReferrers()->toArray()));
     }
 
     public function testReferrerHistoryOnDifferentDays(): void
@@ -92,5 +94,7 @@ class AccompanyingPeriodWorkTest extends TestCase
         self::assertNotFalse($historyA);
         self::assertSame($userA, $historyA->getUser());
         self::assertEquals((new \DateTimeImmutable())->format('Y-m-d'), $historyA->getEndDate()->format('Y-m-d'));
+
+        self::assertTrue(array_is_list($work->getReferrers()->toArray()));
     }
 }