Lock for Veranda fence post caps

Simple locking pin to prevent Veranda 4x4 solar post caps (from Home Depot) from coming detached from their bases. The original post cap is supposed to rotate and lock into place, but it is not secure enough after the cap has been out in the elements for a while. I was having trouble with wind and squirrels knocking the tops off of mine.

These are installed by just supergluing them into one of the screw holes in the top of the cap. Once installed, the 'lock' clicks into place when installing