diff --git a/src/Protocol/OStatus.php b/src/Protocol/OStatus.php
index c7c609f3b9..67c3070fe2 100644
--- a/src/Protocol/OStatus.php
+++ b/src/Protocol/OStatus.php
@@ -52,7 +52,7 @@ class OStatus
 	 *
 	 * @return array Array of author related entries for the item
 	 */
-	private static function fetchAuthor(DOMXPath $xpath, $context, array $importer, array &$contact, $onlyfetch)
+	private static function fetchAuthor(DOMXPath $xpath, $context, array $importer, array &$contact = null, $onlyfetch)
 	{
 		$author = [];
 		$author["author-link"] = XML::getFirstNodeValue($xpath, 'atom:author/atom:uri/text()', $context);