Does a Stone Giant get an attack of opportunity if I move only 5 feet away from it?

It reads in the PHB (p.195)

You can make an opportunity attack when a hostile creature that you can see moves out of your reach.

For a creature who has no melee attacks with only a 5 ft. reach, such as a stone Giant whose Greatclub attack has a reach of 15 ft., would it get an attack of opportunity on me if I move 5 ft. away from a position adjacent to it?