A simple but powerful improvement of the shift-and-add method for the restoration of astronomical images is presented. In this modified algorithm, the shift vector and weight of a specklegram are estimated by computing the cross correlation between the specklegram and the current average before shifting the specklegram and updating the average. In this sense, all the information contained in the specklegrams is used for maximizing the coherence during the averaging process. Numerical simulations indicate that the suggested modification widens the applicability of the shift-and-add method to extended objects without the appearance of ghost images.