  The discrepancies between $b\to s\ell^+\ell^-$ data and the corresponding
Standard Model predictions point to the existence of new physics with a
significance at the $5\sigma$ level. While previously a lepton flavour
universality violating effect was preferred, the new $R(K^{(*)})$ and
$B_s\to\mu^+\mu^-$ measurements are now compatible with the Standard Model,
favouring a lepton flavour universal beyond the Standard Model contribution to
$C_9$. Since heavy new physics is generally chiral, and because of the
stringent constraints from charged lepton flavour violation, this poses a
challenge for model building. In this article, we point out a novel
possibility: a diquark, i.e. a coloured scalar, induces the Wilson coefficient
of the $(\bar s \gamma^\mu P_L b) (\bar c \gamma_\mu P_L c)$ operator at
tree-level, which then mixes into $O_9$ via an off-shell photon penguin. This
setup allows for a lepton flavour universal effect of $C_9\approx-0.5$, without
violating bounds from $\Delta M_s$, $\Delta\Gamma$, $B\to X_s\gamma$ and
$D^0-\bar D^0$ mixing. This scenario predicts a small and negative
$C_9^{\prime}$ and a light diquark, preferably with a mass around $500\,$GeV,
as compatible with the CMS di-di-jet analysis, and a deficit in the inclusive
$b\to c\bar c s$ rate.
