The problem is that I want sensors for triggers or for collecting "coins" or reaching the goal. So I do this: The problem is that when I declare it as a sensor Chipmunk doesn't generate a callback all other code is the same except that line. When I remove that line Chipmunk generates callbacks but it also creates a collision response(the ball bounces back from the coin). This is how I declare callbacks: I only call cpSpaceSetDefaultCollisionHandler function once. I use Chipmunk 5.2.0(I also tried with 5.0.0) and Xcode(GCC).