Univalent Wandering Domains in the Eremenko-Lyubich Class

We use the folding theorem of Bishop to construct an entire function $f$ in class $B$ and a wandering domain $U$ of $f$ such that $f$ restricted to $f^n(U)$ is univalent, for all $n\ge 0$. The components of the wandering orbit are bounded and surrounded by the postcritical set.