diff --git a/public/typo3conf/ext/ep_products/Classes/Service/FilterService.php b/public/typo3conf/ext/ep_products/Classes/Service/FilterService.php
index a5e4e061..dafaa1eb 100644
--- a/public/typo3conf/ext/ep_products/Classes/Service/FilterService.php
+++ b/public/typo3conf/ext/ep_products/Classes/Service/FilterService.php
@@ -47,7 +47,7 @@ class FilterService implements SingletonInterface
                 if (empty($value)) {
                     return [];
                 }
-                return array_map('intval', $value);
+                return array_map('intval', (array) $value);
             });
         }
         $optionsResolver->setNormalizer('bus', function (Options $options, $value) {