The on-the-job collaborative discourse of teachers is said to offer promising insights into the implicit processes of teacher learning and socialisation (Lefstein et al. 2020). Building on existing theory and research, this article examines diagnostic frame disputes in teachers' discussions that involve the negotiation of contradictions between external expectations and teachers' own frames of reference. This phenomenon is illustrated using two purposively-sampled vignettes, drawn from video data generated in two Malaysian secondary schools in 2019. In both vignettes, teachers work to reconcile the discrepancies between how student learning problems are framed by external accountability measures, as well as how the teachers interpret those problems locally, leading to disputes about how to frame those problems. The analysis presents an empirical illustration of how teachers negotiate situated meaning, shedding light on how they interpret and respond to accountability pressures on their practice. Implications for policy and practice are discussed.