diff --git a/phpBB/phpbb/search/fulltext_native.php b/phpBB/phpbb/search/fulltext_native.php
index ea239c0b36..69025fc08f 100644
--- a/phpBB/phpbb/search/fulltext_native.php
+++ b/phpBB/phpbb/search/fulltext_native.php
@@ -437,7 +437,7 @@ class fulltext_native extends \phpbb\search\base
 				// throw an error if we shall not ignore unexistant words
 				else if (!$ignore_no_id && sizeof($non_common_words))
 				{
-					trigger_error(sprintf($user->lang['WORDS_IN_NO_POST'], implode($user->lang['COMMA_SEPARATOR'], $non_common_words)));
+					trigger_error(sprintf($this->user->lang['WORDS_IN_NO_POST'], implode($this->user->lang['COMMA_SEPARATOR'], $non_common_words)));
 				}
 				unset($non_common_words);
 			}