We report on the updated theoretical predictions for the width difference $\Delta \Gamma_s$ and the flavor-specific CP asymmetry $a^s_{\textrm{fs}}$ in the $B_s - \bar{B}_s$ mixing. Working at leading power in the Heavy Quark Expansion we evaluated all previously unknown two-loop contributions to this observable, which marks an important step in the task of reducing uncomfortably
large scale uncertainties stemming from uncalculated QCD corrections.
Our new the Standard-Model prediction for the ratio of the width and mass differences in the $\overline{\textrm{MS}}$ scheme reads $\Delta \Gamma_s/\Delta M_s= (5.20\pm 0.69)\cdot 10^{-3}$.