diff --git a/grade/report/grader/lib.php b/grade/report/grader/lib.php
index fc36cc04167..3bd600dd319 100644
--- a/grade/report/grader/lib.php
+++ b/grade/report/grader/lib.php
@@ -630,6 +630,7 @@ class grade_report_grader extends grade_report {
                 $idnumbercell->attributes['class'] = 'header useridnumber';
                 $idnumbercell->header = true;
                 $idnumbercell->scope = 'row';
+                $idnumbercell->text = $user->idnumber;
                 $userrow->cells[] = $idnumbercell;
             }