![](/static/66c60d9f/assets/icons/icon-96x96.png)
![](https://programming.dev/pictrs/image/8140dda6-9512-4297-ac17-d303638c90a6.png)
While pure Python code should work unchanged, code written in other languages or using the CPython C API may not. The GIL was implicitly protecting a lot of thread-unsafe C, C++, Cython, Fortran, etc. code - and now it no longer does. Which may lead to all sorts of fun outcomes (crashes, intermittent incorrect behavior, etc.).
:tabclose
You should be thankful it’s not 18446744073709551615 days to go.