Vowel deletion in Yine crucially refers to both morphological and phonological information. It has been argued that the process is only analysable in a theory where the phonology has access to morphology, either on the assumption of different morphological domains of constraint evaluation (Lin 1987(Lin , 1997a or on the assumption of morphologically indexed optimality-theoretic constraints (Pater 2009). In contrast, I propose a phonological analysis of vowel deletion in Yine in a parallel Optimality Theory model. The phonology, I assume, has only limited access to morphological information, and can only distinguish between affix and stem material. I argue that the morphemes that trigger deletion of a preceding vowel have a defective underlying representation : they lack a mora, and ' usurp ' the mora of a preceding vowel.