diff --git a/phpstan-baseline-level-3.neon b/phpstan-baseline-level-3.neon
index 0b55309e3..b7091f4ad 100644
--- a/phpstan-baseline-level-3.neon
+++ b/phpstan-baseline-level-3.neon
@@ -783,16 +783,6 @@ parameters:
 			count: 1
 			path: src/Bundle/ChillThirdPartyBundle/Security/Voter/ThirdPartyVoter.php
 
-		-
-			message: "#^Parameter \\#1 \\$thirdParty \\(Chill\\\\ThirdPartyBundle\\\\Entity\\\\ThirdParty\\) of method Chill\\\\ThirdPartyBundle\\\\Serializer\\\\Normalizer\\\\ThirdPartyNormalizer\\:\\:normalize\\(\\) should be contravariant with parameter \\$object \\(mixed\\) of method Symfony\\\\Component\\\\Serializer\\\\Normalizer\\\\NormalizerInterface\\:\\:normalize\\(\\)$#"
-			count: 1
-			path: src/Bundle/ChillThirdPartyBundle/Serializer/Normalizer/ThirdPartyNormalizer.php
-
-		-
-			message: "#^Parameter \\#2 \\$format \\(string\\) of method Chill\\\\ThirdPartyBundle\\\\Serializer\\\\Normalizer\\\\ThirdPartyNormalizer\\:\\:supportsNormalization\\(\\) should be contravariant with parameter \\$format \\(string\\|null\\) of method Symfony\\\\Component\\\\Serializer\\\\Normalizer\\\\NormalizerInterface\\:\\:supportsNormalization\\(\\)$#"
-			count: 1
-			path: src/Bundle/ChillThirdPartyBundle/Serializer/Normalizer/ThirdPartyNormalizer.php
-
 		-
 			message: "#^Parameter \\#1 \\$document \\(Chill\\\\DocStoreBundle\\\\Entity\\\\StoredObject\\) of method Chill\\\\WopiBundle\\\\Service\\\\Wopi\\\\ChillDocumentManager\\:\\:getBasename\\(\\) should be contravariant with parameter \\$document \\(ChampsLibres\\\\WopiLib\\\\Contract\\\\Entity\\\\Document\\) of method ChampsLibres\\\\WopiLib\\\\Contract\\\\Service\\\\DocumentManagerInterface\\:\\:getBasename\\(\\)$#"
 			count: 1
diff --git a/src/Bundle/ChillThirdPartyBundle/Serializer/Normalizer/ThirdPartyNormalizer.php b/src/Bundle/ChillThirdPartyBundle/Serializer/Normalizer/ThirdPartyNormalizer.php
index 5f4cd1a9a..7b2721511 100644
--- a/src/Bundle/ChillThirdPartyBundle/Serializer/Normalizer/ThirdPartyNormalizer.php
+++ b/src/Bundle/ChillThirdPartyBundle/Serializer/Normalizer/ThirdPartyNormalizer.php
@@ -15,6 +15,7 @@ use Chill\MainBundle\Templating\TranslatableStringHelperInterface;
 use Chill\ThirdPartyBundle\Entity\ThirdParty;
 use Chill\ThirdPartyBundle\Entity\ThirdPartyCategory;
 use Chill\ThirdPartyBundle\Templating\Entity\ThirdPartyRender;
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
 use Symfony\Component\Serializer\Normalizer\NormalizerAwareInterface;
 use Symfony\Component\Serializer\Normalizer\NormalizerAwareTrait;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
@@ -35,12 +36,12 @@ class ThirdPartyNormalizer implements NormalizerAwareInterface, NormalizerInterf
         $this->translatableStringHelper = $translatableStringHelper;
     }
 
-    /**
-     * @param ThirdParty $thirdParty
-     * @param string|null $format
-     */
     public function normalize($thirdParty, $format = null, array $context = [])
     {
+        if (!$thirdParty instanceof ThirdParty) {
+            throw new UnexpectedValueException();
+        }
+
         return [
             'type' => 'thirdparty',
             'firstname' => $thirdParty->getFirstname(),