1. A method by a control unit of an engine system, the engine system including a supercharged internal combustion engine, the method comprising: obtaining, by the control unit, a value of an actual boost pressure in the engine system based on first output of a sensor arrangement; obtaining, by the control unit and based on second output of the sensor arrangement, a value of a dynamic variable that more quickly responds to a dynamic change in a state of the engine system than does the actual boost pressure; applying, by the control unit, the obtained actual boost pressure value as input to a first function, which produces a first intermediate variable value based on the input actual boost pressure value; correcting, by the control unit, the intermediate variable value based on the obtained value of the dynamic variable; applying, by the control unit, the corrected intermediate variable value as input to a second function, which produces a first controller variable value based on the input corrected intermediate variable value; obtaining, by the control unit, a setpoint boost pressure value; applying, by the control unit, the obtained setpoint boost pressure value as input to the first function, which produces a second intermediate variable value based on the input setpoint boost pressure value; applying, by the control unit, the second intermediate variable value as input to the second function, which produces a second controller variable value based on the input second intermediate variable value; and controlling, by the control unit, the boost pressure in the engine system based on the first and second controller variables.