We investigate the implications of direct $CP$ violation (CPV) on the determination of the unitarity triangle angle $\ensuremath{\gamma}$ from $B\ensuremath{\rightarrow}DK$ decays. We show that $\ensuremath{\gamma}$ can still be extracted even with the inclusion of direct CPV in charm if (i) at least one of the $D$ decays has negligible $CP$ violation; and (ii) data from a charm factory at threshold are used. If approximate expressions without direct $CP$ violation in charm are used, this can result in a shift in $\ensuremath{\gamma}$ that is $\mathcal{O}({r}_{D}/{r}_{B})$. It is modest for $B\ensuremath{\rightarrow}DK$ but can be $\mathcal{O}(1)$ for $B\ensuremath{\rightarrow}D\ensuremath{\pi}$. We illustrate the size of the shift using an example of the Gronau-London-Wyler method.