The present invention relates to a knife for a sealing jaw arrangement of a filling machine, the knife in use being provided in a first member, and designed to cooperate with a groove of a second member. The knife further has a body being provided with a cutting edge on one side thereof, the body further comprising a guide. The guide is configured to enter the groove for controlling a movement, in use, of the cutting edge into the groove, and the guide is configured to enter the groove before the cutting edge enters the groove. The invention further relates to a sealing jaw assembly having such a knife.