Abstract. We characterize all compact and Hausdorff spaces X which satisfy the condition that for every multiplicative bijection ϕ on C(X, I), there exist a homeomorphism µ : X −→ X and a continuous map p :for every f ∈ C(X, I) and x ∈ X. This allows us to disprove a conjecture of Marovt (Proc. Amer. Math. Soc. 134 (2006Soc. 134 ( ), 1065Soc. 134 ( -1075. Some related results on other semigroups of functions are also given.