A child-proof locking system for a slide fastener includes a slide which engages a pair of molded plastic interlocking strips. The slide is carried in a puller having a proximal grip and a distal latch. When the slide fastener is closed, the puller seats in a strike, with the latch having a plurality of arms abutting a distal end of the strike to lock the puller. To open the slide fastener, the latch arms are pressed inwardly with one hand, to clear the strike, while the grip is pulled away from the strike with the other hand.