An axiomatization for one-way expected utility, $P \succ Q \Rightarrow E(u, P) > E(u, Q)$, is given which places no restriction on the cardinality of the consequence set. In comparison with a previous axiomatization [Ann. Math. Statist. $\mathbf{42}$ (1971) 572-577] for finite consequence sets, the new axioms strengthen the Archimedean property and weaken the order-independence conditions. In particular, the new theory avoids the criticism of indifference due to threshold phenomena that affects the previous axiomatization.