diff --git a/core/lib/Drupal/Core/Config/Entity/DraggableListBuilder.php b/core/lib/Drupal/Core/Config/Entity/DraggableListBuilder.php
index 3fea947..e1eb60e 100644
--- a/core/lib/Drupal/Core/Config/Entity/DraggableListBuilder.php
+++ b/core/lib/Drupal/Core/Config/Entity/DraggableListBuilder.php
@@ -123,7 +123,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
     if (!empty($this->weightKey)) {
       $count = count($this->entities);
       if ($count > 20) {
-        $delta = ceil(count($this->entities) / 2);
+        $delta = ceil($count / 2);
       }
     }
     foreach ($this->entities as $entity) {