[Fyren]

Looking at the disassembly in a random server binary I have, three choices come to mind:

Don't mask the address of the global variable used. This will probably break the signature every update.
If you just want to use it, reimplement it yourself. More work, but you might be able to get something that won't break every update. (Alternative: if you do this work and can find the address of the global, you can patch your signature at runtime?)
Find another function that uses it, then use a signature plus offset to pull the address out of the call.