The Oulipo has claimed that foreign member, Italo Calvino, was a key proponent of the clinamen, a purposeful deviation from the strict constraints in which the group specializes. However, upon closer inspection, Calvino’s Oulipian production during his Paris period does not seem to advance a formalized definition of this tool of constrained writing. This paper elucidates his theorization and subsequent implementation of this fundamental Oulipian principle and argues that it is Calvino’s metaphorical (rather than a strict) use of the clinamen that influenced the Oulipo.