diff --git a/src/Plugin/Field/FieldWidget/EntityqueueDragtableWidget.php b/src/Plugin/Field/FieldWidget/EntityqueueDragtableWidget.php
index 8a6eaeb..83a9ad3 100644
--- a/src/Plugin/Field/FieldWidget/EntityqueueDragtableWidget.php
+++ b/src/Plugin/Field/FieldWidget/EntityqueueDragtableWidget.php
@@ -300,6 +300,14 @@ class EntityqueueDragtableWidget extends EntityReferenceAutocompleteWidget {
     $submitted_values = NestedArray::getValue($form_state->getValues(), array_slice($button['#parents'], 0, -1));
     if (isset($submitted_values['new_item']['target_id'])) {
       $items = $form_state->getFormObject()->getEntity()->get($field_name);
+      // Allow unique records only.
+      $existing_items = $items->getValue();
+      foreach ($existing_items as $value)  {
+        if ($value['target_id'] == $submitted_values['new_item']['target_id']) {
+          return FALSE;
+        }
+      }
+
       $items->appendItem($submitted_values['new_item']);
 
       // Increment the items count.