There is provided mechanisms for shaping cells in a wireless communications network. A method is performed by a network node. The method comprises obtaining spatial channel characteristics of a set of currently and/or previously served terminal devices in the wireless communications network, wherein the spatial channel characteristics are indicative of a current collective first network performance metric value for the set of currently and/or previously served terminal devices. The method comprises identifying, using the spatial channel characteristics, those terminal devices of the set of currently and/or previously served terminal devices that have an individual second network performance metric value below a threshold value by comparing the individual second network performance metric value for each of the currently and/or previously served terminal devices to the threshold value. The method comprises determining beam forming parameters for shaping the cells based on the identified terminal devices, wherein the cells are shaped to increase an individual first network performance metric value for the identified terminal devices, wherein the beam forming parameters give rise to a modified set of terminal devices being served in wireless communications network, and wherein spatial channel characteristics of the modified set of terminal devices are indicative of a new collective first network performance metric value for the modified set of terminal devices. The method comprises providing a notification of the determined beam forming parameters to a radio access network node only when the new collective first network performance metric value is not worse than the current collective first network performance metric value.