We propose and demonstrate a novel four-wave-mixing (FWM) compensator made of a highly nonlinear fiber and a pump laser. This technique utilizes the additional pi/2 phase delay occurring in every FWM process. Thus, the FWM components generated in the transmission fiber can be cancelled out by the FWM components generated within the FWM compensator. We have experimentally confirmed that the proposed technique could effectively suppress the FWM crosstalk generated in the transmission fiber and improve the system's performance.