  We determine the error introduced in a joint halo model analysis of
galaxy-galaxy lensing and galaxy clustering observables when adopting the
standard approximation of linear halo bias. Considering the Kilo-Degree Survey,
we forecast that ignoring the non-linear halo bias would result in up to
5$\sigma$ offsets in the recovered cosmological parameters describing structure
growth, $S_8$, and the matter density parameter, $\Omega_{\mathrm{m}}$. We
include the scales $10^{-1.3}<r_{\rm{p}} \ / h^{-1}\, \mathrm{Mpc}<10$ in the
data vector, and the direction of these offsets are shown to depend on the
freedom afforded to the halo model through other nuisance parameters. We
conclude that a beyond-linear halo bias correction must therefore be included
in future cosmological halo model analyses of large-scale structure observables
on non-linear scales.
