This paper presents the results of an interferometric study of the shock/boundary-layer interaction at a compression corner. The boundary layer upstream of the corner is a non-equilibrium state having been disturbed by injection through a porous surface. As well as being relevant to the design of transpiration-cooled surfaces, the results show many similarities to the interaction in an adverse pressure gradient. The changes in the nature of the interaction as the approaching profile is distorted is fully explored and the results should provide a useful test case for computational fluid mechanics. The results are also used to evaluate the accuracy of interferometric techniques.