In this study, power capture performance of a heaving wave energy converter has been optimized by investigating the effect of variation of power take-off damping. The wave energy converter model used in this study utilizes the sliding discrete Fourier transform technique to estimate the local wave frequency. The power take-off parameters are adjusted according to the estimated wave frequency. As a part of the study, two different cases are evaluated. In the first case, the conventional approach based on using power take-off damping equal to radiation damping which is a function of the estimated wave frequency is considered. In the second part of the study, as a proposed approach, the power take-off damping is calculated with a gain factor. This gain factor varies the hydrodynamic analysis-based frequency-dependent radiation damping by multiplying with it. The results show that the captured power results can be increased from 1.64 to 10.38%, while, in average, the power capture increase covering all datasets is 5.95%.