diff --git a/src/Bundle/ChillDocGeneratorBundle/Serializer/Normalizer/DocGenObjectNormalizer.php b/src/Bundle/ChillDocGeneratorBundle/Serializer/Normalizer/DocGenObjectNormalizer.php
index cbce1a422..11743796a 100644
--- a/src/Bundle/ChillDocGeneratorBundle/Serializer/Normalizer/DocGenObjectNormalizer.php
+++ b/src/Bundle/ChillDocGeneratorBundle/Serializer/Normalizer/DocGenObjectNormalizer.php
@@ -96,10 +96,7 @@ class DocGenObjectNormalizer implements NormalizerAwareInterface, NormalizerInte
         return 'docgen' === $format && (is_object($data) || null === $data);
     }
 
-    /**
-     * @return string|array<string>
-     */
-    private function getExpectedType(AttributeMetadata $attribute, ReflectionClass $reflection): string|array
+    private function getExpectedType(AttributeMetadata $attribute, ReflectionClass $reflection): string
     {
         $type = null;