A method performed by a source base station, comprising: receiving, from a first device of a device-to-device, D2D, cluster, a first measurement report which indicates that a handover of the first device is needed; determining, according to a D2D handover condition, whether to initiate or postpone the handover based on the first measurement report; characterised in that initiating the handover comprises: requesting at least one second measurement report from at least one second device of the D2D cluster if there is no valid measurement report of the at least one second device; requesting a valid first measurement report from the first device if the first measurement report has expired; selecting, according to a predefined criterion, a best target cell or a best target base station for a joint handover of the first device and the at least one second device at least partly based on the valid first and the at least one second measurement reports; and upon a failure of the joint handover to the best target cell or the best target base station, selecting, according to said predefined criterion, a next-best target cell or a next-best target base station based on the valid first and the at least one second measurement reports. receiving, from a first device of a device-to-device, D2D, cluster, a first measurement report which indicates that a handover of the first device is needed; determining, according to a D2D handover condition, whether to initiate or postpone the handover based on the first measurement report; characterised in that initiating the handover comprises: requesting at least one second measurement report from at least one second device of the D2D cluster if there is no valid measurement report of the at least one second device; requesting a valid first measurement report from the first device if the first measurement report has expired; selecting, according to a predefined criterion, a best target cell or a best target base station for a joint handover of the first device and the at least one second device at least partly based on the valid first and the at least one second measurement reports; and upon a failure of the joint handover to the best target cell or the best target base station, selecting, according to said predefined criterion, a next-best target cell or a next-best target base station based on the valid first and the at least one second measurement reports. requesting at least one second measurement report from at least one second device of the D2D cluster if there is no valid measurement report of the at least one second device; requesting a valid first measurement report from the first device if the first measurement report has expired; selecting, according to a predefined criterion, a best target cell or a best target base station for a joint handover of the first device and the at least one second device at least partly based on the valid first and the at least one second measurement reports; and upon a failure of the joint handover to the best target cell or the best target base station, selecting, according to said predefined criterion, a next-best target cell or a next-best target base station based on the valid first and the at least one second measurement reports.