A method for adapting a beam shape of a beam in a wireless communication system having multiple nodes is disclosed. Each node is provided with an antenna system configured to provide radio coverage in a cell by a cell specific beam. The method comprises: calculating a transmit weight vector for each user to be served by a given cell based on information of spatial channel characteristics for the user to be served by the given cell and long term interference characteristics estimated based on aggregated information of spatial channel characteristics for users that the given cell should avoid interfering with and that are served by other cells; performing phase normalization of the calculated transmit weight vectors; and aggregating all transmit weight vectors to establish a common transmit weight vector used to form the beam shape for the cell specific beam.