Concave Collision Polygons

I have been trying to make a Physics based puzzle game, but over the last 2 weeks I have hit a block. I can use concave collision polygons and I need them. I don't know if there is some way to get around this, like by using multiple convex ones or an addon (Box2D). One of my favorite games is called, "And Yet it Moves," This game is made with TGB and does contain some non convex shapes, which leads me to believe there is a loop-hole to make concave collision polygons. Thanks any help or advise would be greatly greatly appreciated.