2024 and we're still having these stupid-ass issues because crusty C codebases can't add a X_ or an X11_ in front of their macros. Every C codebase treating the whole world like its own backyard and not something to share, and then suddenly it's just Infinite Problems.
Please, please just get into the habit of using a prefix. You don't have namespaces. You need to be disciplined. I don't care what you pick as a prefix, just HAVING ONE makes it easy enough to refactor and not break the whole world even if we do have to change it.