The invention relates to adjusting the shape of the antenna beam of a directional antenna in a communications system. According to the invention, the antenna beam is divided into at least a handover beam sector and a main beam sector. The shape of the at least two beam sectors are then adjusted based on different requirements and objectives. The shape of handover beam sector is adjusted based on the handover parameter settings of the communications system, e.g. by adjusting the angular interval of this handover beam sector based on the parameter settings. Optionally, the shape of the main beam sector is adjusted by maximizing the antenna gain of the directional antenna within this beam sector.