Abstract: A plastic sealing member for sealing the housing cup of a round-type galvanic cell, and which is provided with a predetermined breaking point (bursting membrane or score) to prevent explosion of the cell during improper use, is covered on the surface which faces the inside of the cell with a pore-free film of bitumen, a synthetic resin, an adhesive, or a lacquer, at least over the predetermined breaking point and its immediate vicinity, to inhibit stress corrosion cracking which propagates under high mechanical stress and under the effect of the alkaline electrolyte, without reducing the intended bursting pressure.