<html class="reftest-wait"> <head> <style> div { width: 200px; height: 200px; } .positioned { position: absolute; top: 0px; left: 200px; background-color: green; } .outer { position: relative; } </style> </head> <body> <div class="outer"> <div id="test"></div> <div class="positioned"></div> </div> <script> function doTest() { document.getElementById("test").style.backgroundColor = "green"; document.documentElement.removeAttribute("class"); } document.addEventListener("MozReftestInvalidate", doTest); </script> </body> </html>