Source Insight can't recognize multi-line macro

Question

Here is a snippet:

#if defined(a) || \
    defined(b)
void test();
#else
void test();
#endif

Source Insight can't recognize multi-line macro.

It treats

#if defined(a) || \
    defined(b)

as

#if defined(a)
#if defined(a) || defined(b)

How do I fix this?