Galaxies and galaxy clusters are associated with dark matter halos, which are biased tracers of the dark matter distribution. The bias is known to depend on halo mass, and this mass-dependence is sometimes used to constrain galaxy formation models and cosmological parameters. However, such constraints are biased if mass is not the only thing which matters - a possibility which often goes by the name of Assembly Bias, because the way in which a halo's mass was assembled is known to correlate with its environment. I will discuss how the scale dependence of bias - which is generic - can be used to make progress even when assembly bias matters.