diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/ConfigEntityQueryTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/ConfigEntityQueryTest.php
index d0d8b36..3d9a9e4 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/ConfigEntityQueryTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/ConfigEntityQueryTest.php
@@ -63,6 +63,8 @@ protected function setUp() {
     // non-matches on every levels.
     $array['level1']['level2a'] = 9;
     $array['level1a']['level2'] = 9;
+    // The tests match array.level1.
+    $array['level1'] = array(9);
     // The tests match array.level1.level2.
     $array['level1']['level2'] = 1;
     $entity = entity_create('config_query_test', array(
@@ -139,6 +141,12 @@ public function testConfigEntityQuery() {
       ->execute();
     $this->assertResults(array('3'));
 
+    // Filter by array with equality.
+    $this->queryResults = $this->factory->get('config_query_test')
+      ->condition('array', '9')
+      ->execute();
+    $this->assertResults(array('1'));
+
     // Filter by label with a known prefix.
     $this->queryResults = $this->factory->get('config_query_test')
       ->condition('label', 'test_prefix', 'STARTS_WITH')