A container and closure maintain pilferproof characteristics without impairment. The container has a mouth-neck portion having an external thread and an annular anchoring flange located beneath the external thread. The closure is comprised of a cylindrical skirt wall having a circumferentially extending breakable line to divide the skirt wall into a main portion above the breakable line and a pilferproof skirt portion below it. The inner surface of the pilferproof skirt portion has a plurality of circumferentially spaced anchoring flaps extending radially inwardly. A projecting flange projects radially outwardly below the annular anchoring flange. When the closure has been fully mounted on the mouth-neck portion, the lower end of the pilferproof skirt portion contacts or approaches the upper surface of the projecting flange. Furthermore, a plurality of protrusions are spaced circumferentially below the annular anchoring flange on the peripheral surface of the mouth-neck portion. When the closure has been fully mounted on the mouth-neck portion, forward ends of the protrusions contact or approach the inner surface of the pilferproof skirt portion.