diff --git a/grade/edit/tree/lib.php b/grade/edit/tree/lib.php
index 4a86cb3eec4..b9aec5d723c 100644
--- a/grade/edit/tree/lib.php
+++ b/grade/edit/tree/lib.php
@@ -698,9 +698,11 @@ class grade_edit_tree_column_weight extends grade_edit_tree_column {
         }
         $itemcell = parent::get_item_cell($item, $params);
         $itemcell->text = ' ';
+        $object = $params['element']['object'];
 
-        if (!in_array($params['element']['object']->itemtype, array('courseitem', 'categoryitem', 'category'))
-                && !in_array($params['element']['object']->gradetype, array(GRADE_TYPE_NONE, GRADE_TYPE_TEXT))) {
+        if (!in_array($object->itemtype, array('courseitem', 'categoryitem', 'category'))
+                && !in_array($object->gradetype, array(GRADE_TYPE_NONE, GRADE_TYPE_TEXT))
+                && (!$object->is_outcome_item() || $object->load_parent_category()->aggregateoutcomes)) {
             $itemcell->text = grade_edit_tree::get_weight_input($item);
         }
 
diff --git a/grade/edit/tree/outcomeitem_form.php b/grade/edit/tree/outcomeitem_form.php
index aeece1fc75e..285acbed4c3 100644
--- a/grade/edit/tree/outcomeitem_form.php
+++ b/grade/edit/tree/outcomeitem_form.php
@@ -202,7 +202,7 @@ class edit_outcomeitem_form extends moodleform {
 
                 $parent_category->apply_forced_settings();
 
-                if (!$parent_category->is_aggregationcoef_used()) {
+                if (!$parent_category->is_aggregationcoef_used() || !$parent_category->aggregateoutcomes) {
                     if ($mform->elementExists('aggregationcoef')) {
                         $mform->removeElement('aggregationcoef');
                     }
@@ -228,8 +228,11 @@ class edit_outcomeitem_form extends moodleform {
                         $mform->addHelpButton('aggregationcoef', $aggcoef, 'grades');
                     }
                 }
-                // Remove fields used by natural weighting if the parent category is not using natural weighting.
-                if ($parent_category->aggregation != GRADE_AGGREGATE_SUM) {
+
+                // Remove the natural weighting fields for other aggregations,
+                // or when the category does not aggregate outcomes.
+                if ($parent_category->aggregation != GRADE_AGGREGATE_SUM ||
+                        !$parent_category->aggregateoutcomes) {
                     if ($mform->elementExists('weightoverride')) {
                         $mform->removeElement('weightoverride');
                     }
diff --git a/lib/grade/grade_category.php b/lib/grade/grade_category.php
index 3f78e0c111f..1b0e734af90 100644
--- a/lib/grade/grade_category.php
+++ b/lib/grade/grade_category.php
@@ -1454,6 +1454,9 @@ class grade_category extends grade_object {
             if ($gradeitem->gradetype == GRADE_TYPE_NONE || $gradeitem->gradetype == GRADE_TYPE_TEXT) {
                 // Text items and none items do not have a weight.
                 continue;
+            } else if (!$this->aggregateoutcomes && $gradeitem->is_outcome_item()) {
+                // We will not aggregate outcome items, so we can ignore them.
+                continue;
             }
 
             // Record the ID and the weight for this grade item.
@@ -1524,6 +1527,9 @@ class grade_category extends grade_object {
                 // Text items and none items do not have a weight, no need to set their weight to
                 // zero as they must never be used during aggregation.
                 continue;
+            } else if (!$this->aggregateoutcomes && $gradeitem->is_outcome_item()) {
+                // We will not aggregate outcome items, so we can ignore updating their weights.
+                continue;
             }
 
             if (!$gradeitem->weightoverride) {