Abstract: A closure device for packages having at least one self-adhesive closure element is disclosed. It comprises a self-adhesive glue layer (L1, L2) on the closure element, arranged for closing of the package. A release layer (F1, F2) covers the glue layer (L1, L2). At least one tear strip (G1, G2) is provided such that it can be torn through the package when the package is closed to form an opening. The tear strip (G1, G2) is provided on a part of the package forming the closure element, and on one side thereof that is facing inwards when the package is closed. Finally, the tear strip (G1, G2) is provided with a silicone layer on the side thereof facing the material of the package when the package is in a closed condition.