Although officially conceived as a restatement of existing law, section 2109 CCQ relating to fixed price contracts of enterprise differs in many respects from its predecessor (s. 1690 CCLC). We can therefore ask to what extent the adoption of the Quebec Civil Code resulted in, or signalled, a modification of Quebec law on fixed price contracts. In this article, the various interpretations of sections 1690 CCLC and 2109 CCQ are compared, and some of the uncertainties that persist in relation to the interpretation of section 2109 CCQ are underlined. Attempts are then made to account for these uncertainties in light of how the evolution of the concept of contract of enterprise in the course of the 20th century.