What is the best fastener for a side pocket on a backpack?

I bought a Jansport Antics Bulldozer Backpack from Amazon. It has 4 side pockets, secured only by a small Velcro patch. I've already lost an expensive item from one of the pockets because the pocket opened. I want to sew on a more secure fastener. I'm thinking about a pants/skirt hook-and-eye for each pocket. I wonder, though, if it will be secure because there won't always be tension on the hook. Will it work? Do you have a better idea?