  In light of the recent LHCb observation of CP violation in the charm sector,
we review standard model (SM) predictions in the charm sector and in particular
for $\Delta A_{CP}$. We get as an upper bound in the SM $| \Delta A_{CP} ^{\rm
SM}| \leq 3.6 \times 10^{-4}$, which can be compared to the measurement of
$\Delta A_{CP} ^{\rm LHCb2019} = (-15.4 \pm 2.9) \times 10^{-4}$. We discuss
resolving this tension within an extension of the SM that includes a flavour
violating $Z'$ that couples only to $\bar{s}s$ and $\bar{c}u$. We show that for
masses below 80 GeV and flavour violating coupling of the order of $10^{-4}$,
this model can successfully resolve the tension and avoid constraints from
dijet searches, $D^0-\overline{D}^0$ mixing and measurements of the $Z$ width.
