diff --git a/src/Serializer/APIPlatform/DetermineTypeFromElementIRIDenormalizer.php b/src/Serializer/APIPlatform/DetermineTypeFromElementIRIDenormalizer.php
index c2c33f6b..46291fe0 100644
--- a/src/Serializer/APIPlatform/DetermineTypeFromElementIRIDenormalizer.php
+++ b/src/Serializer/APIPlatform/DetermineTypeFromElementIRIDenormalizer.php
@@ -101,7 +101,7 @@ class DetermineTypeFromElementIRIDenormalizer implements DenormalizerInterface,
         return $this->denormalizer->denormalize($data, $type, $format, $context);
     }
 
-    public function supportsDenormalization(mixed $data, string $type, ?string $format = null, array $context = [])
+    public function supportsDenormalization(mixed $data, string $type, ?string $format = null, array $context = []): bool
     {
         //Only denormalize if the _type discriminator is not set and the class is supported and we not have already called this function
         return !isset($context[self::ALREADY_CALLED])
diff --git a/src/Serializer/APIPlatform/OverrideClassDenormalizer.php b/src/Serializer/APIPlatform/OverrideClassDenormalizer.php
index f3458a5b..c8155abc 100644
--- a/src/Serializer/APIPlatform/OverrideClassDenormalizer.php
+++ b/src/Serializer/APIPlatform/OverrideClassDenormalizer.php
@@ -38,7 +38,7 @@ class OverrideClassDenormalizer implements DenormalizerInterface, DenormalizerAw
 
     public const CONTEXT_KEY = '__override_type__';
 
-    public function denormalize(mixed $data, string $type, ?string $format = null, array $context = [])
+    public function denormalize(mixed $data, string $type, ?string $format = null, array $context = []): mixed
     {
         //Deserialize the data with the overridden type
         $overrideType = $context[self::CONTEXT_KEY];