  We provide a time-dependent Dyson map and metric for the two dimensional
harmonic oscillator with a non-Hermitian $i xy$ coupling term. This particular
time-independent model exhibits spontaneously broken $\mathcal{PT}$-symmetry
and becomes unphysical in the broken regime, with the spectrum becoming
partially complex. By introducing an explicit time-dependence into the Dyson
map, we provide a time-dependent metric that renders the model consistent
across the unbroken and broken regimes.
