A closure cover with tamperproof securing means for an open end of a packaging container, a flange which protrudes radially over a container wall being arranged on the packaging container, comprising a front wall, a skirt which is arranged on the edge side on the front wall and defines a longitudinal axis, at least one tamperproof tab, wherein the skirt on its side remote from the front wall forms an open cover end, wherein in an external peripheral region of the front wall a support surface is formed on the side thereof facing the open cover end, said support surface defining a support plane and the skirt bearing against the support surface on the edge side, wherein the skirt is formed by a plurality of skirt parts (19, 20, 21) which are arranged spaced apart from one another in the peripheral direction and the skirt parts (19, 20, 21) are defined in each case on the periphery by skirt part ends (22, 23), and the skirt parts (19,20, 21) are configured so as to be curved in an arcuate manner in the peripheral direction, in particular by circular arc portions, and wherein a free space is configured between the skirt part ends (22, 23) of the skirt parts (19, 20, 21) which face one another in each case in the peripheral direction, wherein the tamperproof tab is arranged in the free space and is connected to the skirt part ends (22, 23) which face one another, and at least one latching means is provided on the tamperproof tab on the side thereof facing the support surface, which latching means in the axial direction is arranged spaced apart from the support plane defined by the support surface, in the direction of the open cover end, and a latching surface facing the support plane is configured on the latching means, wherein the latching surface of the latching means, viewed in the radial direction, is arranged in an overlapping position relative to the support surface, and the axial spacing of the latching means from the support surface serves for receiving a partial portion of the flange and for engaging behind said flange and wherein the latching surface is formed by a first front face of the tamperproof tab and the first front face is arranged continuously spaced apart from the support surface in the peripheral direction, characterised in that the first front face of the tamperproof tab is configured to extend in a linear manner between the skirt part ends (22, 23) which respectively face one another in the peripheral direction, and in that a second front face of the tamperproof tab which is arranged in the region of the open cover end, viewed in the peripheral direction, has an arcuate longitudinal path protruding radially outwardly toward the side remote from the longitudinal axis and extending in a curved manner and in that, viewed in axial section, the tamperproof tab at least in the region of half of the peripheral extent thereof is configured to widen starting from the first front face toward the side remote from the longitudinal axis, and thus the tamperproof tab at least in the central region thereof has an oblique position relative to the longitudinal axis and the oblique position relative to the longitudinal axis in each case reduces toward the skirt part ends (22, 23).