An axial piston pump controller for an axial piston pump having a fixed valve plate and a variable displacement is provided. The axial piston pump controller is configured to determine a displacement of the axial piston pump, and to calculate a pump displacement control current to be supplied to the axial piston pump to control the displacement of the axial piston pump. Calculating the pump displacement control current comprises calculating a nominal value for the pump displacement control current based on a rotational speed of the axial piston pump, calculating a pump stiffness adjustment factor based on a pump stiffness control map having as inputs: an output pressure of the axial piston pump; and the estimated pump displacement, and calculating the pump displacement control current to be supplied to the axial piston pump based on the nominal value and the pump stiffness adjustment factor. The controller is further configured to output an instruction to output the calculated pump displacement control current to the axial piston pump in order to control the displacement of the axial piston pump.