There is provided a photon-counting x-ray detector system (200) comprising a plurality of photon-counting channels (220), and at least one anti-coincidence circuit (230), each of which is connected to least two of the channels and configured to detect coincident events in the connected channels. The x-ray detector system (200) further comprises an anti-coincidence controller (240) configured to control the operation of said at least one anti-coincidence circuit based on photon count information by gradually adapting the operation of said at least one anti-coincidence circuit with increasing count rates, starting from a threshold count rate.
