  We investigate the uncertainty induced by the Higgs-boson mass on the
determination of $m_W$ from the LEP-2 run near the threshold for $W$-pair
production. For a light Higgs boson the Yukawa interaction between the two
slowly-moving $W$ bosons gives rise to a correction of close to 1\% to the
total cross-section. This corresponds to a 15 MeV shift in the deduced $W$ mass
for a Higgs-boson mass of 60 GeV. We present a simple approximation for this
correction and discuss its validity.

High Energy Physics - Phenomenology