Clang-format and boost macros

I'm writing a clang-format file for my research project in C++ in hopes to soothe some of the code review rounds about style. Everything works well, except we use a boost-provided access modifier of "PUBLIC_WITH_TESTS_ELSE_PRIVATE:". Clang-format doesn't seem to know what to do with this, and treats it like a constructor. I didn't see any option to define for custom access modifiers, either. I could of course write a clever script to do it for me, but it would be better if the formatting happened in one place. Does anyone know how to make this work?