In examining reading comprehension in a second language (L2), I have demonstrated that the prevailing metaphor of transfer of skills is misleading, and that what happens is access to an already existing general cognitive skill. There is evidence in first language (L1) and in L2 that accessing this skill when reading in an alphabetic language involves efficient use of verbal working memory (VWM). This article reports a study of a component of VWM, the phonological loop, which serves to hold recently read material available in a phonological form. The study investigated whether the unreliability of learners' mental L2 phonological inventories contributed to reading comprehension problems. Lower intermediate learners with L2 reading comprehension problems attempted to recall similar and dissimilar sequences of words in L1 (French) and L2 (English). Their performance was consistent with their having unreliable L2 phonological inventories; their upper intermediate counterparts, who had no L2 reading comprehension problems, had significantly more reliable L2 phonological inventories. This finding has important implications for the classroom: Rather than attempting to teach components of a cognitive skill that learners already possess, teachers would do better to spend the equivalent time increasing exposure to the spoken language, and improving receptive and productive phonology. (Contains 3 tables, 1 figure, and 3 footnotes.)