diff --git a/mod/assign/lang/en/assign.php b/mod/assign/lang/en/assign.php
index b214864b090..042af511984 100644
--- a/mod/assign/lang/en/assign.php
+++ b/mod/assign/lang/en/assign.php
@@ -187,6 +187,7 @@ $string['graded'] = 'Graded';
 $string['gradedon'] = 'Graded on';
 $string['gradebelowzero'] = 'Grade must be greater than or equal to zero.';
 $string['gradeabovemaximum'] = 'Grade must be less than or equal to {$a}.';
+$string['gradelocked'] = 'This grade is locked or overridden in the gradebook.';
 $string['gradeoutof'] = 'Grade out of {$a}';
 $string['gradeoutofhelp'] = 'Grade';
 $string['gradeoutofhelp_help'] = 'Enter the grade for the student\'s submission here. You may include decimals.';
diff --git a/mod/assign/locallib.php b/mod/assign/locallib.php
index fed15b25c2c..e472da5d5f7 100644
--- a/mod/assign/locallib.php
+++ b/mod/assign/locallib.php
@@ -4086,7 +4086,15 @@ class assign {
             }
         }
 
-        if ($this->grading_disabled($userid, false)) {
+        // See if this user grade is locked in the gradebook.
+        $gradinginfo = grade_get_grades($this->get_course()->id,
+                                        'mod',
+                                        'assign',
+                                        $this->get_instance()->id,
+                                        array($userid));
+        if ($gradinginfo &&
+                isset($gradinginfo->items[0]->grades[$userid]) &&
+                $gradinginfo->items[0]->grades[$userid]->locked) {
             return false;
         }
 
@@ -5137,7 +5145,7 @@ class assign {
 
 
     /**
-     * Determine if this users grade is locked or overridden.
+     * Determine if this users grade can be edited.
      *
      * @param int $userid - The student userid
      * @param bool $checkworkflow - whether to include a check for the workflow state.
@@ -5271,11 +5279,17 @@ class assign {
             // Use simple direct grading.
             if ($this->get_instance()->grade > 0) {
                 $name = get_string('gradeoutof', 'assign', $this->get_instance()->grade);
-                $gradingelement = $mform->addElement('text', 'grade', $name);
-                $mform->addHelpButton('grade', 'gradeoutofhelp', 'assign');
-                $mform->setType('grade', PARAM_TEXT);
-                if ($gradingdisabled) {
-                    $gradingelement->freeze();
+                if (!$gradingdisabled) {
+                    $gradingelement = $mform->addElement('text', 'grade', $name);
+                    $mform->addHelpButton('grade', 'gradeoutofhelp', 'assign');
+                    $mform->setType('grade', PARAM_RAW);
+                } else {
+                    $mform->addElement('hidden', 'grade', $name);
+                    $mform->hardFreeze('grade');
+                    $mform->setType('grade', PARAM_RAW);
+                    $strgradelocked = get_string('gradelocked', 'assign');
+                    $mform->addElement('static', 'gradedisabled', $name, $strgradelocked);
+                    $mform->addHelpButton('gradedisabled', 'gradeoutofhelp', 'assign');
                 }
             } else {
                 $grademenu = make_grades_menu($this->get_instance()->grade);