Katharine Jenkins argues that Sally Haslanger’s focal analysis of gender problematically excludes non-passing trans women from the category “woman.” However, Jenkins does not explain why this exclusion contradicts the feminist aims of Haslanger’s account. In this paper, I advance two arguments that suggest that a trans-inclusive account of “woman” is crucial to the aims of feminism. I claim that the aims of feminism are to understand and combat women’s oppression. First, I argue that denial of trans identities reinforces cultural ideas that perpetuate both transphobic violence and sexual violence against women. Consequently, a feminist account of “woman” that fails to respect trans identities indirectly contributes to the oppression of women. Second, I prove that non-passing trans women are oppressed as women through the internalization of sexual objectification. I then conclude that an account of “woman” that excludes non-passing trans women cannot successfully advance a complete understanding of women’s oppression.