Lens retainer EOS 5D Mk2

I have a canon EOS5D Mk2 with 24-105 EF lens - lens is fitted with a lens hood. When carrying the camera the zoom lens extends all by itself which is annoying.
I made a retainer from TPU 95A that fits in the hotshoe and connects to the lens hood - this prevents the lens from extending.
Infill 100%