  We study M5 branes on $\mathbb{R}^{1,1} \times$Taub-NUT that we view as a
singular fibration. Reducing the M5 branes along the fiber gives 5d SYM. Due to
the singularity, this 5d theory has a gauge anomaly and it is not
supersymmetric. To cure these problems we add a supersymmetric gauged chiral
WZW theory on the 2d submanifold where the circle fiber vanishes. In addition
we add a mass term for the five scalar fields located on this submanifold. With
all this, we obtain a fully supersymmetric and gauge invariant theory.
