The present research aimed to examine young and older adults' comprehension of negated text to determine the locus of older adults' difficulty in understanding this text construction. Participants were asked to read short passages at their own pace, complete a lexical decision task, and answer a comprehension question about what they had read. Older adults' comprehension accuracy was lower than that of young adults for passages containing transformational negation. This suggests that limited working memory resources led to older adults' difficulty with negation, not a difficulty with inhibition, as what would have been suggested with difficulties with deactivation negation.