Previous studies have demonstrated the existence of non-native gemination in the speech of native (L1) Italian learners of a second language (L2), corresponding to double letters. We present the results of a bimodal truncated word-matching experiment testing phonological expectations for 30 L1 Italian learners of L2 French, and 30 L1 French control speakers. Manipulated consonantal durations affected responses and response times for learners, but not for native speakers: stimuli with lengthened consonants corresponding to single-letter spelling resulted in lower accuracy and higher response times; stimuli with short consonants corresponding to double-letter spelling resulted in high accuracy, but response times increased. We argue that exposure to native French in the classroom and during stays abroad has promoted the development of fuzzy L2 phonological representations, so that learners correctly process words spelled with double letters but cannot turn off their perceptual sensitivity to consonant duration, which remains modulated by orthography.