<p>Racialized gatekeeping in introductory mathematics courses is an international, systemic concern. However, research on instruction often focuses on classroom-level changes, which can provide limited guidance for the department-level reforms that are necessary to implement instructional change in coordinated, introductory courses. Furthermore, reform efforts can overlook historically dominant values that may be invisibly embedded within departmental structures and the discipline of mathematics, and can lead to incremental changes that fall short of providing equitable educational opportunities. To better understand how departmental values and dynamics may impede the advancement of equity-oriented reform in postsecondary mathematics departments, we present a case study of a mathematics department at a large U.S. university engaged in improving racial equity within its calculus program. Informed by critical whiteness studies, we take as given that whiteness is present throughout this equity-oriented initiative. We explore the nature of how whiteness is reproduced, and what role mathematics plays in the reproduction of whiteness. Findings exhibit how disciplinary values around rigor and quantification masked whiteness in the reform effort, and stymied the department’s stated equity-oriented goals. Implications are provided for equity-oriented change, both departmental and epistemological, in mathematics.</p>