# How to avoid subsurf distortions on cylindrical objects?

I made a cylindrical object which transitions to a squarish block. However there is some distortion at the transition:

If I add a loopcut to get a nicer surface there, it gives the cylinder a not-very-round edge:

What are some topological tricks for getting smooth subsurf without interfering with other parts of the model?

• Thanks for asking this question. Ever since I can remember I've had similar problem. Haven't found the satisfactory solution yet, though :(. Maybe somebody here'll find it. – Paul Gonet Oct 29 '15 at 20:49