The present invention relates to a drill guide for positioning a bone tunnel in which the drill guide comprises a depth stop. The drill guide comprises an aimer arm and a drill sleeve, and includes a sleeve channel. The drill sleeve is moveable towards and away from the distal end of the aimer arm within the sleeve channel, and the depth stop is adjustable to provide a fixed drilling path length, irrespective of the distance between drill sleeve and distal end of the aimer arm.