The concept of institutional complementarity plays an important role in the comparative analysis of capitalism. It has often been criticised for being too static and too functionalist, unable to explain change because it would propose a view of institutional forms fitting perfectly with one another. After having presented the concept and its interest for comparative capitalism, this article argues in favour of its usefulness to explain institutional change. However, in order to be integrated fruitfully into a theory of institutional change, it is necessary to have a political economy definition of complementarity, which should not take institutions as some sort of inputs in a production function, but as socio-political compromises established in historically-specific conditions.