A tongue shaped friction lock is integrally formed in a dust cover or a bottom panel of an open-topped container and positioned to capture the stacking tabs of an adjacent open-topped container. The friction lock provides a small opening through which a stacking tab may be inserted, while at the same time pushing up a locking flap, which pivots up and frictionally engages the stacking tab. A strip of reinforcing tape is embedded within the dust cover and allows one to remove and reuse the dust cover without tearing the tongue lock or the surrounding portions of the dust cover.