diff --git a/grade/report/grader/lib.php b/grade/report/grader/lib.php
index cb3f837f46e..1b82a20ee6e 100644
--- a/grade/report/grader/lib.php
+++ b/grade/report/grader/lib.php
@@ -1911,7 +1911,7 @@ class grade_report_grader extends grade_report {
 
         // Sourced from tablelib.php
         // Check the full name display for sortable fields.
-        if (has_capability('moodle/site:viewfullnames', context_system::instance())) {
+        if (has_capability('moodle/site:viewfullnames', $this->context)) {
             $nameformat = $CFG->alternativefullnameformat;
         } else {
             $nameformat = $CFG->fullnamedisplay;