A blade-disk assembly of a turbomachine is provided, the blade-disk assembly having a plurality of adjacent rotor blades and a closure blade which are tilted into an anchoring groove, and at least one circumferential retention element which interlockingly cooperates with at least one blade, as well as a plurality of tilt-out prevention elements which are disposed between the groove base and the root portions and which, in the rest state, space the blades from the groove base when in the upper position. The blade-disk assembly further has a locking element, a portion of which is located between the groove base and the root portions and which, in the rest state, spaces the closure blade from the groove base when in the upper position. A method for assembling such a blade-disk assembly, as well as a turbomachine, is also provided.