International teaching assistants (ITAs) are criticized for having 'unintelligible' accents for professional communication in Global North English-medium universities. Furthermore, this criticism takes a racist form as it is frequently directed at racially minoritized ITAs. This article complicates this narrative by considering how the disciplinary cultures in which ITAs work influence racist perceptions of and expectations about their accents. Drawing on interviews with engineering ITAs in Ontario, Canada, the article details how the communication conventions and gendered racism of engineering made the ITAs' accents professionally inadequate and outlined what they should sound like. This was done through microaggression learning, the informal learning that the ITAs underwent through experiencing microaggressions based on raciolinguistic ideologies and engineering norms. The article concludes by suggesting reforms within engineering to combat the linguistic and gendered racism of the field.