diff --git a/grade/edit/tree/index.php b/grade/edit/tree/index.php
index e48643de75c..81dfe816e4d 100644
--- a/grade/edit/tree/index.php
+++ b/grade/edit/tree/index.php
@@ -368,6 +368,14 @@ if ($moving) {
 
 echo $OUTPUT->container_end();
 
+$PAGE->requires->yui_module('moodle-core-formchangechecker',
+    'M.core_formchangechecker.init',
+    array(array(
+        'formid' => 'gradetreeform'
+    ))
+);
+$PAGE->requires->string_for_js('changesmadereallygoaway', 'moodle');
+
 echo $OUTPUT->footer();
 
 // Restore original show/hide preference if moving
diff --git a/grade/edit/tree/lib.php b/grade/edit/tree/lib.php
index c05eb927c5a..ba65d9d994e 100644
--- a/grade/edit/tree/lib.php
+++ b/grade/edit/tree/lib.php
@@ -671,6 +671,7 @@ class grade_edit_tree_column_aggregation extends grade_edit_tree_column_category
         } else {
             $attributes = array();
             $attributes['id'] = 'aggregation_'.$category->id;
+            $attributes['class'] = 'ignoredirty';
             $aggregation = html_writer::label(get_string('aggregation', 'grades'), 'aggregation_'.$category->id, false, array('class' => 'accesshide'));
             $aggregation .= html_writer::select($options, 'aggregation_'.$category->id, $category->aggregation, null, $attributes);
             $action = new component_action('change', 'update_category_aggregation', array('courseid' => $params['id'], 'category' => $category->id, 'sesskey' => sesskey()));