The dispersion relation of the drift waves is studied in the presence of a fluctuating electric field consisting of a superposition of small-amplitude, linear, independent drift waves. It is shown that a stabilization effect appears due to the perturbation of particle trajectories, consisting in the partial destruction of the small clumps. A transient process during the increase of the drift instability is revealed. It leads to a stabilization of waves with the largest wavenumbers, before reaching the final nonlinear stage.