A method of and a device for folding a bottom of a package, which includes a sleeve of packaging material with a transversal seal in the end of the bottom forming portion of the package, the portion having the shape of a fin. The method includes folding the fin and forming primary flaps, breaking corners on the folded fin between the primary flaps and the edge between the part of the sleeve forming the bottom and the rest of the sleeve, such that secondary flaps are folded in between the primary flaps and the fin, the secondary flaps thereby being folded essentially towards each other, folding the primary flaps towards each other, and pressing the primary flaps towards the remaining part of the bottom forming part of the sleeve.
