Abstract: The safety apparatus for locking slatted roller shutters is disposed in a channel-shaped shutter rail provided on the side of the roller shutter and comprises a locking device, which is connected to one end of a shutter slat and pivoted to the end of a lower slat. The locking device consists of a chain, which with its lower end is indirectly or directly secured to said lower shutter slat and which has flat links, which have sharp-edged and/or pointed ends and which are pivoted on axes which extend substantially in the longitudinal direction of the roller slats. When an upward pushing force is exerted on the roller shutter from below, the chain will automatically wedge itself between the two mutually opposite legs of the shutter rail. No locking action will be exerted on the roller shutter.