  We find evidence that superconductivity intrudes into the
paramagnetic-to-magnetic transition of the Kondo lattice model if magnetic
frustration is added. Specifically, we study by variational method the model on
a square lattice in the presence of both nearest- ($t$) and
next-nearest-neighbor ($t^\prime$) hopping of the conduction electrons. We find
that when $t^\prime/t$ is finite a $d$-wave superconducting dome emerges
between the magnetic and paramagnetic metal phases and close to the compensated
regime, i.e., the number of conduction electrons equal to the number of
localized spin-1/2 moments. Superconductivity is further strengthened by a
direct antiferromagnetic exchange between the localized moments, to such an
extent that we even observe coexistence with magnetic order.
