Odd Job warning?

I've been trying to get things on my "to-do" list for selling the house done. Most of them are little things that will make the house look better, but not necessarily be an issue. Anyway, one of those was putting the hydraulic closer back on the kitchen storm door. We have lots of kids going in/out of that door and they have a bad tendency to NOT close the door. As a result, one of my cats likes to wander out and go exploring. Not what I want him to do. So, it was one I fixed last week. What I didn't do was warn my husband that I'd fixed (or was going to fix) the door. So he came in, set down his computer case with the intent of turning around and closing the door, when *WHAM!* the door closed... on his head.

Oops..