  We investigate gauge coupling unification for F-theory respectively Type IIB
orientifold constructions of SU(5) GUT theories with gauge symmetry breaking
via non-trivial hypercharge flux. This flux has the non-trivial effect that it
splits the values of the three MSSM gauge couplings at the string scale, thus
potentially spoiling the celebrated one-loop gauge coupling unification. It is
shown how F-theory can evade this problem in a natural way.
