diff --git a/grade/grading/form/lib.php b/grade/grading/form/lib.php
index b69ee82ef2e..1e483e34973 100644
--- a/grade/grading/form/lib.php
+++ b/grade/grading/form/lib.php
@@ -448,6 +448,25 @@ abstract class gradingform_controller {
         }
     }
 
+    /**
+     * If instanceid is specified and grading instance exists and it is created by this rater for
+     * this item, this instance is returned.
+     * Otherwise new instance is created for the specified rater and itemid
+     *
+     * @param int $instanceid
+     * @param int $raterid
+     * @param int $itemid
+     * @return gradingform_instance
+     */
+    public function get_or_create_instance($instanceid, $raterid, $itemid) {
+        global $DB;
+        if ($instanceid &&
+                $instance = $DB->get_record('grading_instances', array('id'  => $instanceid, 'raterid' => $raterid, 'itemid' => $itemid), '*', IGNORE_MISSING)) {
+            return $this->get_instance($instance);
+        }
+        return $this->create_instance($raterid, $itemid);
+    }
+
     /**
      * Returns the HTML code displaying the preview of the grading form
      *
diff --git a/mod/assignment/lib.php b/mod/assignment/lib.php
index 6ffe5387c82..3526369fbd8 100644
--- a/mod/assignment/lib.php
+++ b/mod/assignment/lib.php
@@ -615,6 +615,7 @@ class assignment_base {
 
         //make user global so we can use the id
         global $USER, $OUTPUT, $DB, $PAGE;
+
         $mailinfo = optional_param('mailinfo', null, PARAM_BOOL);
 
         if (optional_param('next', null, PARAM_BOOL)) {
@@ -1077,7 +1078,8 @@ class assignment_base {
                 if (!empty($submission->id)) {
                     $itemid = $submission->id;
                 }
-                $mformdata->advancedgradinginstance = $controller->create_instance($USER->id, $itemid);
+                $instanceid = optional_param('advancedgradinginstanceid', 0, PARAM_INT);
+                $mformdata->advancedgradinginstance = $controller->get_or_create_instance($instanceid, $USER->id, $itemid);
             } else {
                 $advancedgradingwarning = $controller->form_unavailable_notification();
             }
@@ -2389,6 +2391,7 @@ class mod_assignment_grading_form extends moodleform {
 
         $grademenu = make_grades_menu($this->_customdata->assignment->grade);
         if ($gradinginstance = $this->use_advanced_grading()) {
+            $mform->addElement('hidden', 'advancedgradinginstanceid', $gradinginstance->get_id());
             $gradinginstance->get_controller()->set_grade_range($grademenu);
             $mform->addElement('grading', 'advancedgrading', get_string('grade').':', array('gradinginstance' => $gradinginstance));
         } else {