  We investigate possible tests of CPT invariance on the level of event rates
at neutrino factories. We do not assume any specific model, but
phenomenological differences in the neutrino-antineutrino masses and mixing
angles in a Lorentz invariance preserving context, which could be induced by
physics beyond the Standard Model. We especially focus on the muon neutrino and
antineutrino disappearance channels in order to obtain constraints on the
neutrino-antineutrino mass and mixing angle differences. In a typical neutrino
factory setup simulation, we find, for example, that $|m_3 - \bar{m}_3|
\lesssim 1.9 \cdot 10^{-4} \mathrm{eV}$ and $|\theta_{23} -\bar \theta_{23}|
\lesssim 2^\circ$.
