diff --git a/tests/src/Kernel/EntityStringIdTest.php b/tests/src/Kernel/EntityStringIdTest.php
index e0b148f..59ed4c7 100644
--- a/tests/src/Kernel/EntityStringIdTest.php
+++ b/tests/src/Kernel/EntityStringIdTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\search_api\Kernel;
 
+use Drupal\Component\Uuid\Php;
 use Drupal\entity_test\Entity\EntityTestStringId;
 use Drupal\KernelTests\KernelTestBase;
 use Drupal\search_api\Entity\Index;
@@ -150,6 +151,8 @@ class EntityStringIdTest extends KernelTestBase {
       array('short_string_id'),
       // String ID that is not a valid machine name.
       array('http://drupal.org'),
+      // String ID generated randomly. This is to test the length of the Id.
+      [(new Php())->generate()],
     );
   }
 }