diff --git a/mod/assign/locallib.php b/mod/assign/locallib.php
index cebdddca43a..5a1644274b2 100644
--- a/mod/assign/locallib.php
+++ b/mod/assign/locallib.php
@@ -2329,7 +2329,7 @@ class assign {
                 $uniqueid = 0;
                 if ($submission->blindmarking && !$submission->revealidentities) {
                     if (empty($submission->recordid)) {
-                        $uniqueid = self::get_uniqueid_for_user_static($submission->assignment, $user->id);
+                        $uniqueid = self::get_uniqueid_for_user_static($submission->assignment, $grader->id);
                     } else {
                         $uniqueid = $submission->recordid;
                     }