  The massless fermions of a Weyl semimetal come in two species of opposite
chirality, in two cones of the band structure. As a consequence, the current
$j$ induced in one Weyl cone by a magnetic field $B$ (the chiral magnetic
effect, CME) is cancelled in equilibrium by an opposite current in the other
cone. Here we show that superconductivity offers a way to avoid this
cancellation, by means of a flux bias that gaps out a Weyl cone jointly with
its particle-hole conjugate. The remaining gapless Weyl cone and its
particle-hole conjugate represent a single fermionic species, with renormalized
charge $e^\ast$ and a single chirality $\pm$ set by the sign of the flux bias.
As a consequence, the CME is no longer cancelled in equilibrium but appears as
a supercurrent response $\partial j/\partial B=\pm(e^\ast e/h^2)\mu$ along the
magnetic field at chemical potential $\mu$.
