It is pointed out that the widely used formula $dE/dx \sim \alpha^2T2 \ln(ET/m_D2)$ due to Bjorken (and various improvements thereof) do(es) not take into account the running of the coupling. Due to asymptotic freedom the mended result for the QCD collisional energy-loss is much less sensitive to the jet energy $E$ as previously estimated. Implications of the parametrically different behavior are discussed with regard to heavy ion collisions.