diff -u b/core/tests/Drupal/Tests/Core/Render/ElementTest.php b/core/tests/Drupal/Tests/Core/Render/ElementTest.php
--- b/core/tests/Drupal/Tests/Core/Render/ElementTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/ElementTest.php
@@ -38,8 +38,6 @@
     $this->assertCount(2, $properties);
     $this->assertContains('#property1', $properties);
     $this->assertContains('#property2', $properties);
-    $this->assertNotContains('property3', $properties);
-    $this->assertNotContains(0, $properties);
   }
 
   /**