diff --git a/library/includes/functions.php b/library/includes/functions.php
index ead1f5fb8..850a344ef 100644
--- a/library/includes/functions.php
+++ b/library/includes/functions.php
@@ -1592,7 +1592,7 @@ function build_topic_pagination($url, $replies, $per_page)
     return $pg;
 }
 
-function print_confirmation($tpl_vars)
+function print_confirmation($tpl_vars): void
 {
     global $template, $lang;