Abstract: The invention provides a wind turbine having a system for positioning the rotor in an azimuthal reference position Azref and for maintaining it therein for a predetermined period of time, the wind turbine being arranged in test mode. Said rotor positioning system comprises a first controller (31) configured to generate a generator speed reference ?ref from the difference between the rotor azimuthal reference position Azref and the rotor azimuthal measured position Azmeas and a second controller (35) configured to generate a generator torque reference Tref from the difference between said generator speed reference ?ref and the generator speed measured ?meas.