We tested the hypothesis that the orthographic representations (‘spellings’) of second language (L2) words affect experienced L2 speakers’ pronunciation. In Italian, double consonant letters represent geminate (long) consonants. We predicted that Italian speakers of English would pronounce English words with longer consonants if spelled with double letter, e.g. a longer [t] in kitty than city. Three groups of Italian speakers of English performed different word production tasks with different stimuli: acoustic, acoustic and orthographic, or orthographic. The target voiceless stop consonants were presented inside 9 word pairs, spelled with one or two letters. Acoustic and auditory analyses revealed that the target consonants were longer in words spelled with double than with singleton letters, regardless of task. We argue that L2 speakers decode L2 orthographic representations using L1 orthography-phonology correspondences. This affects their pronunciation, even leading to the establishment of a phonological contrast (singleton-geminate) that is unattested in the target language.