Abstract: The blades (3) of a turbine of axial design are inserted into an undercut blade groove (2) of the turbine rotor (1) in a positive-locking manner and are secured by a blade lock. The blade lock comprises a mounting space (7), which is in connection with the blade groove (2) and into which a filler piece (8), which is in positive-locking relationship with the blade foot (6) of the blades (3), and a wedge (9) are inserted. The cross section of the mounting space (7) receiving the filler piece (8) is widened conically beginning from the blade groove (2). The cross section of the filler piece (8) is adapted to the cross section of the mounting space (7).