  In our article in MCU'2013 we state the the Domino problem is undecidable for
all Baumslag-Solitar groups $BS(m,n)$, and claim that the proof is a direct
adaptation of the construction of a weakly aperiodic subshift of finite type
for $BS(m,n)$ given in the paper. In this addendum, we clarify this point and
give a detailed proof of the undecidability result. We assume the reader is
already familiar with the article in MCU'2013.
