diff --git a/bundle/QueryType/SearchQueryType.php b/bundle/QueryType/SearchQueryType.php
index 7bd4365e..1a547163 100644
--- a/bundle/QueryType/SearchQueryType.php
+++ b/bundle/QueryType/SearchQueryType.php
@@ -95,6 +95,10 @@ private function sortKeyAllowed(string $key): bool
         return array_key_exists(trim($key), $this->sortKeysAllowed);
     }
 
+    /**
+     * @param string[] $keys
+     * @return bool
+     */
     private function sortKeysAllowed(array $keys): bool
     {
         foreach ($keys as $key) {