  The stopping force is the force exerted on a charged projectile by the excess
charge of the wake generated by the projectile in the surrounding plasma. Since
the wake does not instantly adjust to the projectile velocity, the stopping
force should be affected by the projectile deceleration caused by the stopping
force itself. We address this effect by deriving the corresponding correction
to the stopping force in a cold plasma. We find that if the projectile is an
ion, the correction is small when the stopping force is due to the plasma
electrons, but can be significant when the stopping force is due to the ions.
