Can't draw a perfect circle with gpanot?

I'm trying to draw an arc with gpanot and I get an oval instead of a circle because the radius is specified in degrees. Of course, 1 degree of longitude is not the same as 1 degree of latitude, so the farther North I go, the less circular the arc.

Is there someway to specify the radius in nautical miles? Might there be a clever way to fix it with projection.

Thanks,
-Chris Lauer