  We present a determination of the charm-quark mass in the MSbar scheme using
the data combination of charm production cross section measurements in
deep-inelastic scattering at HERA. The framework of global analyses of the
proton structure accounts for all correlations of the charm-quark mass with the
other non-perturbative parameters, most importantly the gluon distribution
function in the proton and the strong coupling constant alpha_s(M_Z). We obtain
at next-to-leading order in QCD the value m_c(m_c) = 1.15 +- 0.04 (exp)
+0.04/-0.00 (scale) GeV and at approximate next-to-next-to-leading order
m_c(m_c) = 1.24 +- 0.03 (exp) +0.03/-0.02 (scale) +0.00/-0.07 (theory) GeV with
an accuracy competitive with other methods.
