HTML5 Cache

When I update files for a game via Dropbox, it caches it. Isn't there a way in HTML5 to turn off caching in the header? Is there a way to work around this other than turning off caching in my browser? I want to make sure people that I send my links to have the most up-to-date version of the game. I send the same people the updated versions. It is just a very tedious task for them to force reload pages and for me to tell people who are not aware of caching that they need to press Ctrl + R.

The games still update even though they are cached for offline use, although sometimes you have to refresh twice to get the update. You can also detect updates being available and prompt to reload the page automatically. More info in Offline games in Construct 2.