diff --git a/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php b/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php
index 8c75c98..0cf9502 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php
@@ -340,7 +340,7 @@ protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS')
 
     // If 'target_bundles' is NULL, all bundles are referenceable, no further
     // conditions are needed.
-    if (isset($handler_settings['target_bundles']) && !is_null($handler_settings['target_bundles'])) {
+    if (isset($handler_settings['target_bundles']) && is_array($handler_settings['target_bundles'])) {
       // If 'target_bundles' is an empty array, no bundle is referenceable,
       // force the query to never return anything and bail out early.
       if ($handler_settings['target_bundles'] === []) {