Missing favicon.ico is blocked by CSP?

How do I get rid of this error:

Code:

Content Security Policy: The page’s settings blocked the loading of a resource at [url=http://localhost/favicon.ico]http://localhost/favicon.ico[/url] (“default-src”).

This is the browser defaulting to a favicon probably because I haven't set one specifically. But how do I get rid of this? I've tried looking into the CSP of CI4 but it makes no sense in this regard. The browser is asking for a 'default' (expected) favicon.ico which I don't want to provide ... how do I tell the browser to go f... itself (in a nice and polite way of course ;  ) )?

Where do I whitelist stuff for this?