  The order of the thermal transition in the chiral limit of QCD with two
dynamical flavours of quarks is a long-standing issue. Still, it is not
definitely known whether the transition is of first or second order in the
continuum limit. Which of the two scenarios is realized has important
implications for the QCD phase diagram and the existence of a critical endpoint
at finite densities. Settling this issue by simulating at successively
decreased pion mass was not conclusive yet. Recently, an alternative approach
was proposed, extrapolating the first order phase transition found at imaginary
chemical potential to zero chemical potential with known exponents, which are
induced by the Roberge-Weiss symmetry. For staggered fermions on $N_t=4$
lattices, this results in a first order transition in the chiral limit. Here we
report of $N_t=4$ simulations with Wilson fermions, where the first order
region is found to be large.
