  We report the first detection of an optical millisecond pulsar with the fast
photon counter Aqueye+ in Asiago. This is an independent confirmation of the
detection of millisecond pulsations from PSR J1023+0038 obtained with SiFAP at
the Telescopio Nazionale Galileo. We observed the transitional millisecond
pulsar PSR J1023+0038 with Aqueye+ mounted at the Copernicus telescope in
January 2018. Highly significant pulsations were detected. The rotational
period is in agreement with the value extrapolated from the X-ray ephemeris,
while the time of passage at the ascending node is shifted by $11.55 \pm 0.08$
s from the value predicted using the orbital period from the X-rays. An
independent optical timing solution is derived over a baseline of a few days,
that has an accuracy of $\sim 0.007$ in pulse phase ($\sim 12$ $\mu$s in time).
This level of precision is needed to derive an accurate coherent timing
solution for the pulsar and to search for possible phase shifts between the
optical and X-ray pulses using future simultaneous X-ray and optical
observations.
