diff --git a/admin/settings/grades.php b/admin/settings/grades.php
index 53c9ee3a509..d2cc43ebcb9 100644
--- a/admin/settings/grades.php
+++ b/admin/settings/grades.php
@@ -60,7 +60,7 @@ if (has_capability('moodle/grade:manage', $systemcontext)
 
         $temp->add(new admin_setting_configtext('grade_export_userprofilefields', new lang_string('gradeexportuserprofilefields', 'grades'), new lang_string('gradeexportuserprofilefields_desc', 'grades'), 'firstname,lastname,idnumber,institution,department,email', PARAM_TEXT));
 
-        $temp->add(new admin_setting_configtext('grade_export_customprofilefields', new lang_string('gradeexportcustomprofilefields', 'grades'), new lang_string('gradeexportcustomprofilefields_desc', 'grades'), null, PARAM_TEXT));
+        $temp->add(new admin_setting_configtext('grade_export_customprofilefields', new lang_string('gradeexportcustomprofilefields', 'grades'), new lang_string('gradeexportcustomprofilefields_desc', 'grades'), '', PARAM_TEXT));
 
         $temp->add(new admin_setting_configcheckbox('recovergradesdefault', new lang_string('recovergradesdefault', 'grades'), new lang_string('recovergradesdefault_help', 'grades'), 0));