[NiLuJe]

Try adding -ansi to your CFLAGS. If it doesn't break anything, that'll make sure no c99 symbols get pulled.

EDIT: If you don't care about portability (in this case, it shouldn't matter, we know that our target system will always be Linux/glibc 2.5), -D_GNU_SOURCE is another way to workaround this (and is probably less likely to break stuff). That's what I usually do in the sscanf case, in fact.