Let (K < L, v) be a valued field extension and g be a continuous ring endomorphism of L. We are interested in the K-vector space structure of L equipped with g and v. This can be studied in the language of "valued module" that we will introduce during the talk. We will then classify the C-minimal valued modules (C-minimality is a generalization of o-minimality for ultrametric structures; for instance, C-minimal fields are exactly the algebraically closed valued fields).