Rocket Loader - Does not use passive listeners to improve scrolling performance

At Google Page Speed I get this warning:
Does not use passive listeners to improve scrolling performance.
Consider marking your touch and wheel event listeners as passive to improve your page’s scroll performance.
https://ajax.cloudflare.com/cdn-cgi/scripts/7089c43e/cloudflare-static/rocket-loader.min.js line:0

Can anyone help?

I’m pretty sure this is just Rocket Loader passing along a JS listener from your site. If you disable Rocket Loader, you will probably find out which of your JS is triggering this.