  Bonicatto--Pasqualetto--Rajala (2020) proved that a decomposition theorem for
sets of finite perimeter into indecomposable sets, known to hold in Euclidean
spaces, holds also in complete metric spaces equipped with a doubling measure,
supporting a Poincar\'e inequality, and satisfying an \emph{isotropicity}
condition. We show that the last assumption can be removed.
