diff --git a/src/Extractor/HttpClient.php b/src/Extractor/HttpClient.php
index aef36d47..72407a21 100644
--- a/src/Extractor/HttpClient.php
+++ b/src/Extractor/HttpClient.php
@@ -409,7 +409,7 @@ private function getReferer($url, $httpHeader = [])
      * @param string $url        Absolute url
      * @param array  $httpHeader Custom HTTP Headers from SiteConfig
      *
-     * @return ?string
+     * @return string|null
      */
     private function getCookie($url, $httpHeader = [])
     {