diff --git a/lib/Client/Options/ModSearch/ModSearchOptions.php b/lib/Client/Options/ModSearch/ModSearchOptions.php
index c486064..ef81b1b 100644
--- a/lib/Client/Options/ModSearch/ModSearchOptions.php
+++ b/lib/Client/Options/ModSearch/ModSearchOptions.php
@@ -154,10 +154,10 @@ public function getSortOrder(): ?SortOrder
     }
 
     /**
-     * @param string|null $sortOrder
+     * @param SortOrder|null $sortOrder
      * @return $this
      */
-    public function setSortOrder(?string $sortOrder): static
+    public function setSortOrder(?SortOrder $sortOrder): static
     {
         $this->sortOrder = $sortOrder;
         return $this;