c rand() function and ISAAC random number generator

I wrote a program in C that uses a number of different random number generators and one of them is ISAAC (available at http://ift.tt/1ekws3u). It works well but the problem is that in rand.h rand() is redefined as a macro. In my program I want to use the standard C rand() function as well. I tried changing the name of the macro to rand12() but I cannot see any other place in ISAAC that the macro is called so this doesn't work.

Could you offer some ideas how I can keep the standard rand() function and use ISAAC as well?