core/tests/Drupal/Tests/Core/Render/ElementTest.php | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/core/tests/Drupal/Tests/Core/Render/ElementTest.php b/core/tests/Drupal/Tests/Core/Render/ElementTest.php
index 8220d99..75c0645 100644
--- a/core/tests/Drupal/Tests/Core/Render/ElementTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/ElementTest.php
@@ -195,6 +195,9 @@ public function providerTestIsEmpty() {
       [['#cache' => ['tags' => ['foo']]], TRUE],
       [['#cache' => ['contexts' => ['bar']]], TRUE],
 
+      [['#cache' => [], '#markup' => 'llamas are awesome'], FALSE],
+      [['#markup' => 'llamas are the most awesome ever'], FALSE],
+
       [['#cache' => [], '#any_other_property' => TRUE], FALSE],
       [['#any_other_property' => TRUE], FALSE],
     ];