  We experimentally study electron transport between two superconducting indium
leads, coupled to a single WTe$_2$ crystal, which is a three-dimensional Weyl
semimetal. We demonstrate Josephson current in long 5~$\mu$m In-WTe$_2$-In
junctions, as confirmed by the observation of integer (1,2,3) and fractional
(1/3, 1/2, 2/3) Shapiro steps under microwave irradiation. Demonstration of
fractional a.c. Josephson effect indicates multivalued character of the
current-phase relationship, which we connect with Weyl topological surface
states contribution to Josephson current. In contrast to topological insulators
and Dirac semimetals, we do not observe $4\pi$ periodicity in a.c. Josephson
effect for WTe$_2$ at different frequencies and power, which might reflect
chiral character of the Fermi arc surface states in Weyl semimetal.
