  We investigate wide-angle photoproduction of the $\eta'$ meson within the
handbag approach to twist-3 accuracy. It turns out that, due to the gluon
content of the $\eta'$, this process is dominated by twist-2 in contrast with
pion and $\eta$ photoproduction. Using the presently available information on
the twist-2 and twist-3 distribution amplitudes and on the $\eta - \eta'$
mixing, we provide prediction for the $\eta'$ cross section and helicity
correlations. It is argued that $\eta'$ photoproduction is well suited to
improve our knowledge of the two-gluon distribution amplitude.
