diff --git a/src/Bundle/ChillMainBundle/Serializer/Normalizer/DateNormalizer.php b/src/Bundle/ChillMainBundle/Serializer/Normalizer/DateNormalizer.php
index 3050ad268..032fa484d 100644
--- a/src/Bundle/ChillMainBundle/Serializer/Normalizer/DateNormalizer.php
+++ b/src/Bundle/ChillMainBundle/Serializer/Normalizer/DateNormalizer.php
@@ -17,6 +17,7 @@ use DateTimeInterface;
 use IntlDateFormatter;
 use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 use Symfony\Component\HttpFoundation\RequestStack;
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
 use Symfony\Component\Serializer\Normalizer\ContextAwareNormalizerInterface;
 use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
 use function array_key_exists;
@@ -36,15 +37,20 @@ class DateNormalizer implements ContextAwareNormalizerInterface, DenormalizerInt
 
     public function denormalize($data, string $type, ?string $format = null, array $context = [])
     {
+        if (null === $data) {
+            return null;
+        }
+
         switch ($type) {
             case DateTime::class:
                 return DateTime::createFromFormat(DateTimeInterface::ISO8601, $data['datetime']);
 
             case DateTimeInterface::class:
             case DateTimeImmutable::class:
-            default:
                 return DateTimeImmutable::createFromFormat(DateTimeInterface::ISO8601, $data['datetime']);
         }
+
+        throw new UnexpectedValueException();
     }
 
     public function normalize($date, ?string $format = null, array $context = [])