--- /dev/null
+--- src/Plugin/views/field/DraggableViewsField.php
++++ src/Plugin/views/field/DraggableViewsField.php
+@@ -63,14 +63,14 @@ class DraggableViewsField extends BulkForm {
+ $form[$this->options['id']][$row_index]['id'] = array(
+ '#type' => 'hidden',
+ '#value' => $row->{$this->definition['entity field']},
+- '#attributes' => array('class' => 'draggableviews-id'),
++ '#attributes' => array('class' => array('draggableviews-id')),
+ );
+
+ // Add parent.
+ $form[$this->options['id']][$row_index]['parent'] = array(
+ '#type' => 'hidden',
+ '#default_value' => $draggableviews->getParent($row_index),
+- '#attributes' => array('class' => 'draggableviews-parent'),
++ '#attributes' => array('class' => array('draggableviews-parent')),
+ );
+ }
+