Three profoundly deaf individuals undertook a low-frequency backward lexical translation task (French/English), where morphological structure was manipulated and orthographic distance between test items was measured. Conditions included monomorphemic items (simplex), polymorphemic items (complex), items whose French morphological structure exceeded their English counterpart (mismatch), and a control. Order of translation success was uniform: control > mismatch > simplex > complex, as was order for false-cognate errors: complex > simplex > mismatch, patterning precisely with hearing participants (Janke and Kolokonte, 2014). We discuss how these results highlight a route for future studies to disentangle phonology and orthography further from morphology in first-language interference.