A device is arranged for determining a first distance according to a ranging protocol using a measurement message from a second device. A cooperating device (130) has a directional antenna (133) and is located at a trusted distance (150) sharing a connecting direction (160) with the first device. The cooperating device determines a third direction of the same measurement message, and transfers support data to the first device based on the third direction. The first device first determines a first angle (161) between the first direction and the connecting direction and obtains a third angle (163) between the third direction and the connecting direction using the support data. Then a verification test is performed on the first distance (151), the trusted distance (150), the first and the third angle. The first distance is reliable when said distances and angles correspond to a viable spatial constellation (100) of the devices.