A cap for sealing a container having a lug-type closure assembly is described. The cap has a top panel and a circumferential side wall panel. The top panel is positioned about a longitudinal axis and extends radially outwardly therefrom. The circumferential side wall panel is integral with an outer peripheral edge of the top panel and has first second, and third segments. The first segment extends downwardly. The second segment extends radially outwardly at a first angle to the first segment. The third segment extends downwardly from the second segment at a second angle to the second segment.