Door Top Hook

thingiverse

There are two versions, V3 is just over the size of a regular door while V4 is just under the size of a regular door. Each only has a few millimeters of difference, but V4 is intended to be heated (either with a heat gun/hair drier or hot water) so it can be warped and stretched to fit around your door tightly. The door should still be able to close with this on top, but if your door fits tight it may need some sanding.