  We show that contrary to naive expectations the recently observed diphoton
excess can be explained by a vector resonance, which decays to a photon and a
light scalar $s$, followed by a decay of the scalar into two photons: $Z'
\rightarrow \gamma s \rightarrow 3 \gamma$. As the two photons from the scalar
decay are highly boosted, the experimental signature is an apparent diphoton
final state. In fact all the necessary ingredients are naturally present in
$Z'$ models: Additional fermions with electroweak quantum numbers are required
in order to render the theory anomaly free and naturally induce the required
effective couplings, while the hidden Higgs which gives mass to the $Z'$ can be
very light. In particular no new coloured states are required in this
framework. We also show that in such a setup the width of the resonance can be
rather large, while all couplings remain perturbative.
