I want to ensure that data I request via an AJAX call is fresh and not cached. Therefor I send the header `Cache-Control: no-cache`

But my Chrome Version 33 overrides this header with `Cache-Control: max-age=0` if the user presses F5.

Example. Put a `test.html` on your webserver with the contents

```
<script>
    var xhr = new XMLHttpRequest;
    xhr.open('GET', 'test.html');
    xhr.setRequestHeader('Cache-Control', 'no-cache');
    xhr.send();
</script>

```

In the chrome debugger on the network tab I see the test.html AJAX call. Status code 200. Now press F5 to reload the page. There is the max-age: 0, and status code 304 Not Modified. 

Firefox shows a similar behavior. Intead of just overwriting the request header it modifies it to Cache-Control: no-cache, max-age=0 on F5.

Can I suppress this?