diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php
index 2534474..b590de9 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php
@@ -120,7 +120,8 @@ protected function getOptions(FieldableEntityInterface $entity) {
         ->getSettableOptions(\Drupal::currentUser());
 
       // Add an empty option if the widget needs one.
-      if ($empty_option = $this->getEmptyOption()) {
+      $empty_option = $this->getEmptyOption();
+      if (!empty($empty_option)) {
         $options = $empty_option + $options;
       }
 
@@ -196,8 +197,9 @@ protected function sanitizeLabel(&$label) {
   /**
    * Returns the empty option and label to add to the list of options, if any.
    *
-   * @return array|null
-   *   Either _none as a key and value as a label of the empty option, or NULL.
+   * @return array
+   *   Either '_none' as a key and value as a label of the empty option, or an
+   *   empty array if widget does not support empty option.
    */
   protected function getEmptyOption() { }