  We present an updated analysis of isospin-violating corrections to
$\varepsilon'/\varepsilon$ in the framework of chiral perturbation theory,
taking advantage of the currently improved knowledge on quark masses and
nonperturbative parameters. The role of the different ingredients entering into
the analysis is carefully assessed. Our final result is
$\Omega_{\mathrm{eff}}=0.110\,{}^{+0.090}_{-0.088}$.
