attribute format printf and wchar_t??

[Jim Marshall]

I have a function like this:

int my_wprintf(int lvl, const wchar_t* fmt, ...);

I would love to utilize __attribute__((format(printf,2,3))) but because 
the function uses a wchar_t the compiler balks at it:

  error: format string argument not a string type

Is there a way to use this with wchar functions?

Thanks