A fuze for a projectile has a firing assembly for firing a main charge of the projectile and a delay detonator for firing the firing assembly after a delay time which is defined by a burning distance of a delay charge. The delay detonator has a housing with a fuze half in which it is fired and a detonator half which contains a detonator charge for firing the firing assembly. In order to prevent the projectile from misfiring as a result of premature detonation of the delay detonator, the housing has a relief opening in the fuze half, with an opening cross section that can be passed through freely in the firing state of the delay detonator.