diff --git a/src/Model/Post/Engagement.php b/src/Model/Post/Engagement.php
index a9e1bbfbda..4070112752 100644
--- a/src/Model/Post/Engagement.php
+++ b/src/Model/Post/Engagement.php
@@ -88,7 +88,7 @@ class Engagement
 		$searchtext = self::getSearchTextForItem($parent);
 		if (!$store) {
 			$tags     = array_column(Tag::getByURIId($item['parent-uri-id'], [Tag::HASHTAG]), 'name');
-			$language = !empty($parent['language']) ? array_key_first(json_decode($parent['language'], true)) : '';
+			$language = !empty($parent['language']) ? (array_key_first(json_decode($parent['language'], true)) ?? '') : '';
 			$store    = DI::userDefinedChannel()->match($searchtext, $language, $tags, $mediatype);
 		}