A method for detecting a decoy source of a satellite radionavigation signal, the method being executed by a satellite radionavigation signal reception device comprising two receivers, the method comprising the steps of: for each signal received by the reception device and transmitted by a different satellite, estimating the phase of the signal received by each receiver, computing the estimated phase difference for each receiver, comparing the phase differences computed for multiple different satellites and, if at least two phase differences computed for two different satellites are substantially identical, concluding that a decoy source is present.