Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for updating phonetic dictionaries. In one aspect, a method includes accessing a phonetic dictionary that identifies terms and one or more phonetic representations associated with each term, determining that a particular term that is identified in the phonetic dictionary is a spelling correction for another term that is identified in the phonetic dictionary, and storing, in the phonetic dictionary, one or more of the phonetic representations associated with the other term, with the particular term that is a spelling correction for the other term.