space between * and identifier in function definition

I noticed that when I run the following through GNU indent (2.2.9):

void
foo(XEvent *event)
{
   /* Do something */
}

The output is formatted as (notice the space between * and event):

void
foo(XEvent * event)   <<<--- look here
{
   /* Do something */
}

Whereas if I format the following:

void
foo(int *ptr)
{
   /* Do something */
}

It comes out unchanged.

The problem seems to occur anytime the pointer points to a non-
primitive data type.

Is this a known issue?  I can't find a documented option to
control the behavior -- is there one?