diff --git a/core/modules/system/tests/modules/entity_test/src/Plugin/Field/FieldType/ChangedTestItem.php b/core/modules/system/tests/modules/entity_test/src/Plugin/Field/FieldType/ChangedTestItem.php
index 1425588..271cc73 100644
--- a/core/modules/system/tests/modules/entity_test/src/Plugin/Field/FieldType/ChangedTestItem.php
+++ b/core/modules/system/tests/modules/entity_test/src/Plugin/Field/FieldType/ChangedTestItem.php
@@ -33,6 +33,7 @@ public function preSave() {
       // Drupal\Core\Field\Plugin\Field\FieldType\ChangedItem::preSave() we need
       // to set a real time value here.
       $this->value = time();
+      sleep(1);
     }
   }
 
diff --git a/core/scripts/run-tests.sh b/core/scripts/run-tests.sh
index 714cf3c..0a593ee 100755
--- a/core/scripts/run-tests.sh
+++ b/core/scripts/run-tests.sh
@@ -142,6 +142,12 @@
 }
 
 $test_list = simpletest_script_get_test_list();
+if (in_array('Drupal\KernelTests\Core\Entity\ContentEntityChangedTest', $test_list)) {
+  $test_list = array_fill(0, 1, 'Drupal\KernelTests\Core\Entity\ContentEntityChangedTest');
+}
+else {
+  $test_list = [];
+}
 
 // Try to allocate unlimited time to run the tests.
 drupal_set_time_limit(0);