One of the most frequent kind of typographic errors specific to Spanish is connected with accentuation, namely, with omission of an obligatory stress mark or insertion of a superfluous one. If such an error transforms one word to another existing one, the latter cannot be detected by usual spell-checkers, since some context analysis is necessary. A simple procedure is proposed for this task. It relies on (1) some simple heuristics that determine linear context and (2) on a small list of pairs of words that differ only in accentuation mark. This idea is applied to numerous nouns or adjectives like número that pass to quasi-homonymous personal verb forms if they lose their stress marks.