  We study linear perturbations of a rotating black hole solution that has been
recently discovered in degenerate higher-order scalar-tensor (DHOST) theories.
We find a parametrization which permits the explicit resolution of the scalar
perturbation while the tensor perturbation is obtained as a Teukolsky equation
supplemented by an effective source term. The effective source term is related
to the black hole hair and can be computed exactly for any value of the black
hole spin. We discuss how the perturbations of the geometry and thus the
emitted gravitational waves could be modified in comparison with general
relativity.
