Journal article: This article uses a competence-based approach to the firm in order to analyse the recent destabilisation of internal labour markets. We argue that increasing knowledge codification made possible by the diffusion of information and communication technologies has made competences less dependent upon individuals. Knowledge has been increasingly embodied in firms themselves, which has played an important role in lowering the relative cost of human resource management strategies based on external labour flexibility. As a consequence, recourse to external labour markets has developed,which may harm firms' innovative capabilities in the long run.