Purge Tower Hanging Off Plate

I do not do much in the way of multi-color prints so maybe the shape has been different for a while but that is minor.
How do I stop the purge tower from hanging over the edge of the build plate and throwing an error.
Right now I just move it onto the plate and all is well.
Seems like the act of slicing it would position the tower completely on the plate rather than hanging off the edge.
Purge Tower