User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:41.0) Gecko/20100101 Firefox/41.0 Build ID: 20151014143721 Steps to reproduce: Example page: https://ponyfoo.com/articles/es6-promises-in-depth (archived: https://web.archive.org/web/20150928184517/http://ponyfoo.com/articles/es6-promises-in-depth) There is an anchor link "What is a promise?" whose source HTML is <a href="#what-is-a-promise">What is a Promise?</a> Turn on Reader View, and hover over the link. Actual results: The element became <a href="https://ponyfoo.com/articles/#what-is-a-promise">What is a Promise?</a> and clicking on it, of course, brings you to a page with no "#what-is-a-promise" node. Expected results: The href should have stayed the same: <a href="#what-is-a-promise">What is a Promise?</a>