  Analysis of a large set of phase-resolved $K$-band spectra of the cataclysmic
variable WZ Sge shows that the secondary star of this system appears to be an
L-dwarf. Previous $K$-band spectra of WZ Sge found that the CO overtone
bandheads were in emission. We show that absorption from the $^{\rm
12}$CO$_{\rm (2,0)}$ bandhead of the donor star creates a dip in the $^{\rm
12}$CO$_{\rm (2,0)}$ emission feature. Measuring the motion of this feature
over the orbital period, we construct a radial velocity curve that gives a
velocity amplitude of K$_{\rm abs}$ = 520 $\pm$ 35 km s$^{\rm -1}$, consistent
with the previously published values for this parameter.
