This paper considers the problem of phase correction on Passive Radar using opportunity targets present in the target area. The proposed technique has very low hardware and computational requirements and can be applied to configurations where it is desirable, or necessary, to have dispersed receivers, such as in a multistatic passive radar system, avoiding the use of costly methods. The main idea is to take advantage of a reference target, with a known position, to correct the phase error on the several channels. Simulation results illustrating the effectiveness and limitations of the proposed methodology are presented.