To provide a method for configuring a field device, and a corresponding parameterization system, that enables secure transfer of parameter values via a potentially unsafe data link the method establishes a data link (3) between the field device and a parameterization unit, a parameterization value is transmitted by the parameterization unit to the field device, a parameterization value is received by the field device. Furthermore, a first test value is generated by the parameterization unit from the parameterization value, a second test value is generated by the field device from the received parameterization value. Then, the test values are compared to one another.