A method of controlling a wind turbine comprising at least one rotor blade, and at least one accelerometer housed within a nacelle or a tower of the wind turbine. The method comprises: determining a whirling mode frequency for the wind turbine; measuring an acceleration signal that is indicative of the movement of the nacelle of the wind turbine; determining a frequency spectrum of the measured acceleration signal in the proximity of the determined whirling mode frequency; determining a characteristic value that is representative of the energy content of the measured acceleration signal having the determined frequency spectrum; and performing at least one control action if the characteristic value exceeds a predetermined threshold.