Using the small-flow-time expansion in the gradient-flow formalism, we use the PCAC relation to obtain the strange and charm quark mass by combining the perturbative results for the matching coefficients of the quark currents with lattice data.

We claim that calculating vacuum expectation values of flowed operators on the lattice and in perturbation theory allows one to derive the quark masses in the MS scheme. Here we provide the required perturbative results.