  The uncertainties due to limited knowledge of the multi-hadron final state on
the measurements of the top mass at future linear colliders are discussed. The
study is performed for E+E- -> tt-bar annihilation events at the centre-of-mass
energy of 500 GeV using Monte Carlo models tuned to LEP experiments. The
uncertainties are determined for the all hadronic top-decay mode as well as for
the lepton-plus-jets channel.
