The patch looks right. I'm not sure if this can still be changed in Py3.8, though, since that has been around for quite a while now.

Admittedly, few people will disable the C accelerator module and thus whitness this issue, but for them, this is a breaking change, and some code might rely on the current behaviour. I have no way to tell how much, and whether it intentionally relies on it.

I'd definitely change this for 3.9 and later. Maybe for 3.8, but it's at least a bit of a risk, given that there will only be very few more minor releases for it, and given that this is how things have been working for years. So, rather not, unless there is a convincing argument for backporting the change.