Using Boolean modifier deforms the model when it is Smooth Shaded

Hi all, I am currently coming across a problem with my shark model that is Shade Smooth when using the Boolean Modifier.

This is what the model looked like before using the Boolean Modifier:

This is what the model looks like now, after using the Boolean Modifier:

As you can see, there are unwanted creases at the edges of the shark’s mouth that I want to get rid of.

Any help would be appreciated, thanks :slight_smile:

These are just shading artifacts I would imagine. Turn on auto-smooth and set the angle to something like 60 degrees, what happens then?