  Complex Langevin simulations provide an alternative to sample path integrals
with complex weights and therefore are suited to determine the phase diagram of
QCD from first principles. Adaptive step-size scaling and gauge cooling are
used to improve the convergence of our simulations. We present results for the
phase diagram of QCD in the limit of heavy quarks and discuss the order of the
phase transitions, which are studied by varying the spatial simulation volume.
