$p_{\rm{T}}$-differential cross section of electrons from heavy-flavour hadron decays measured in \pPb collisions at \sqrtsNN $= 8.16 \rm TeV$ compared with the pp reference at the same centre-of-mass energy obtained from the measurement in pp collisions at \sqrts $= 13 \rm TeV$ scaled to \sqrts $= 8.16 \rm TeV$.