diff --git a/src/Bundle/ChillCalendarBundle/Form/CalendarType.php b/src/Bundle/ChillCalendarBundle/Form/CalendarType.php
index f6e4d2baa..753eb3728 100644
--- a/src/Bundle/ChillCalendarBundle/Form/CalendarType.php
+++ b/src/Bundle/ChillCalendarBundle/Form/CalendarType.php
@@ -188,7 +188,7 @@ class CalendarType extends AbstractType
                     }
                     return $location->getId();
                 },
-                function (?string $id): Location {
+                function (?string $id): ?Location {
                     return $this->om->getRepository(Location::class)->findOneBy(['id' => (int) $id]);
                 }
             ))