A method of adjusting the transmission time of a signal in a radio link, the method being performed by a transmitter configured to transmit the signal over the radio link to a receiver and comprising the steps of ascertaining an accuracy that the receiver assumes for the transmitter's clock, calculating an assumed drift of the transmitter's clock based on the assumed accuracy of that clock and the time since a previous correlation between the transmitter's clock and the receiver's clock; and transmitting the signal at a time dependent on the assumed drift.