我如何强制一个favicon刷新?

I have a Grails application running locally using its own tomcat and I have just changed the favicon for a new one. Problem is that I can't see it in any browser. The old favicon shows up or I get no favicon at all, but not my new one. I don't think this is a Grails issue per se, more an issue wth favicons.I have a Grails application running locally usi