diff --git a/report/progress/index.php b/report/progress/index.php
index a3105fe18575a..487330ec7ed2f 100644
--- a/report/progress/index.php
+++ b/report/progress/index.php
@@ -147,7 +147,7 @@ function csv_quote($value) {
         implode(' AND ', $where),
         $where_params,
         $group,
-        $firstnamesort ? 'u.firstname ASC' : 'u.lastname ASC',
+        $firstnamesort ? 'u.firstname ASC, u.lastname ASC' : 'u.lastname ASC, u.firstname ASC',
         $csv ? 0 : COMPLETION_REPORT_PAGE,
         $csv ? 0 : $start,
         $context