--- a/src/Plugin/views/filter/EREFNodeTitles.php
+++ b/src/Plugin/views/filter/EREFNodeTitles.php
@@ -138,7 +138,7 @@
   /**
    * {@inheritdoc}
    */
-  public function init(ViewExecutable $view, DisplayPluginBase $display, array &$options = NULL) {
+  public function init(ViewExecutable $view, DisplayPluginBase $display, ?array &$options = NULL) {
     parent::init($view, $display, $options);
     $this->getRelationships = $this->view->getHandlers('relationship');
     if ($this->getRelationships === NULL) {