_Bool type is broken

I am trying to make a binding to a function that looks like,

bool function (const char *);

and it just doesn't work. bool is a macro for the _Bool type in C99.
Anyway, when I run the c2hs, I get the following.

```
ex.chs:59: (column 3) [ERROR] >>> Internal wrapper error!
Something went wrong generating a bare structure wrapper.
makeArg:arg=False
```

any ideas?
thanks