This paper investigates the effects of orthography on second language (L2) phonology. We replicate a study by Bassetti and Atkinson (2015) investigating the intrusion of silent consonants in production; while the original study was conducted on L1 Italian learners of L2 English, we focus on L1 French learners of L2 English. We recruited 110 French undergraduate students specialising in English in various French universities and we ran two tests to elicit the production of 7x2 target words containing silent letters. In the first task (reading aloud task) participants saw the spelling of target words, while in the second task (word repetition task), participants initially saw their spelling, but then the spelling vanished before beginning the production. The results show that: 1) participants were significantly affected by spelling in both tasks and produced a high proportion of intrusive consonants prompted by silent letters; and 2) when orthographic input was present, more intrusive consonants corresponding to silent letters were produced. These results extend the findings of the original study on Italian participants to French participants. Furthermore, since French (contrary to Italian) has a relatively opaque spelling system, these results suggest that silent letters can have an effect on L2 pronunciation not only for learners with a transparent L1 orthographic system, but also for those who have an opaque L1 orthographic system.