  The momentum diffusion coefficient of a heavy quark in a hot QCD plasma can
be extracted as a transport coefficient related to the correlator of two
colour-electric fields dressing a Polyakov loop. We determine the perturbative
renormalization factor for a particular lattice discretization of this
correlator within Wilson's SU(3) gauge theory, finding a ~12% NLO correction
for values of the bare coupling used in the current generation of simulations.
The impact of this result on existing lattice determinations is commented upon,
and a possibility for non-perturbative renormalization through the gradient
flow is pointed out.
