diff --git a/tests/src/Unit/TruncateHTMLTest.php b/tests/src/Unit/TruncateHTMLTest.php
index fc9998c..efda9cc 100644
--- a/tests/src/Unit/TruncateHTMLTest.php
+++ b/tests/src/Unit/TruncateHTMLTest.php
@@ -49,6 +49,12 @@ class TruncateHTMLTest extends UnitTestCase {
         '',
         '“I <em>really, rea</em>',
       ],
+      [
+        'Maximum nesting level protection.'  . str_repeat("<h4>Hello world</h4>", 500),
+        3,
+        '',
+        'Max',
+      ],
     ];
   }