  We present an update of the measurement of alpha_s(m_tau) from ALEPH tau
hadronic spectral functions. We report a study of the perturbative
prediction(s) showing that the fixed-order perturbation theory manifests
convergence problems not presented in the contour-improved calculation.
Potential systematic effects from quark-hadron duality violations are estimated
to be within the quoted systematic errors. The fit result is alpha_s(m_tau) =
0.344 +- 0.005 +- 0.007, where the first error is experimental and the second
theoretical. After evolution, the alpha_s(M_Z) determined from tau data is the
most precise one to date, in agreement with the corresponding NNNLO value
derived from Z decays.
