diff --git a/docs/tests/procedural-cosmetic-filters.html b/docs/tests/procedural-cosmetic-filters.html
index 714ea1acd..450cbd14d 100644
--- a/docs/tests/procedural-cosmetic-filters.html
+++ b/docs/tests/procedural-cosmetic-filters.html
@@ -182,6 +182,11 @@
     <code>#pcf #a20 b:upward(.fail)</code>
     </div>
 
+<div id="a21" class="tile">
+    <div class="pass"><div class="fail"><a><b></b></a></div></div>
+    <code>#pcf #a21 b:upward(.fail):style(visibility: hidden !important)</code>
+    </div>
+
 </div>
 
 <script>