Disclosed is a closure cap (1) comprising a exterior marginal web (5), a shielding section (4) that protrudes past the marginal web (5), and a hot-melt adhesive (11) which is arranged in the area of the shielding section (4) and is deformable in a plastic manner when heated above a softening temperature. A number of gripping abutment elements (7) are embodied on the marginal web (5) while a joint zone (3) having a reduced flexural rigidity is configured between the marginal web (5) and the shielding section (4). The distance between the abutment elements (7) and the bottom side of the hot-melt adhesive, which faces the marginal web (5), is smaller than the thickness of the material of a basic part (13) in the area of the opening such that an initial tension is created in the joint zone (3) when the closure cap (1) is inserted into the opening, resulting in a simple self-acting closing process after heating the hot-melt adhesive (11).