Method and differential-lock control apparatus for differential lock control are disclosed. A control unit is arranged for communication with an engine speed sensor, a differential-lock activation control, and a differential lock. The control unit is adapted to allow for reduction of an engine speed to a desired engine speed if the engine speed is at least a threshold engine speed in response to receipt of an activate-differential-lock request signal, and adapted to subsequently output an activate-differential-lock control signal to the differential lock so as to command activation of the differential lock.