Changing outside radius on corners to Inside radius

How can I change the radius of a square corner to inside instead of outside?

In shape properties. Do a negative number on corner radius.


Thanks. I tried that and it changed itself to 0.0

Which version of LightBurn? Inner radius on rectangles wasn’t always supported. (It also only works if you use the Shape Properties for a rectangle or square - the Radius tool on the left-side toolbar doesn’t support negative radius)