[en] We present progress towards a measurement of the quantity δα_Had⁽⁵⁾(m_Z²), which represents the variation in the value of the electromagnetic coupling constant α between q² = 0 and m_Z² due to the effects of the 5 lightest quark flavors. This quantity is one of the leading uncertainties in the global electroweak fits performed at the Z pole, and thus on the indirect determination of the Higgs boson mass. We obtain this quantity from an integral of the cross section for e⁺e^- → q q-bar γ, where the photon originates from initial-state radiation (ISR)