The invention relates to a safety arrangement of an elevator, which includes sensors configured to indicate functions that are critical to the safety of the elevator, and also a safety circuit, with which the data formed by the sensors indicating the safety of the elevator is read. The safety arrangement includes a drive device including a control circuit of a motor bridge, an input circuit for a safety signal that can be disconnected/connected from outside the drive device, and also drive prevention logic, to prevent the passage of control pulses to the control poles of high-side and/or low-side switches of the motor bridge when the safety signal is disconnected. The safety circuit brings the elevator into a state preventing a run by disconnecting the safety signal and removes the state preventing a run by connecting the safety signal.