The subtraction technique is a powerful tool for studying nonequilibrium phenomena in manybody systems at short times. Its major limitation lies in the long-time noise due to the Lyapunov divergence of initially close trajectories in phase space. We present a method to compute transport coefficients even when long-time tails are present, with a subtraction technique modified by adding a kind of frictional force field to monitor the phase-space divergence. The price to be paid is to perform an extrapolation of the results to zero field.