Apparatus for driving fasteners includes a barrel, a fastener guide which retreats as the apparatus is pressed against a substrate, a feed magazine, receiving a loader of fasteners, and a safety element configured to allow a fastener to be driven only after the fastener guide has retreated. There is a safety shoe configured to, when there is no fastener in the barrel, be moved into a safe position and prevent the retreat of the fastener guide, and including a tell-tale of the safe position of the safety shoe.