We present new evidence on the impact of a reform that introduced Catalan-Spanish bilingual education in Catalonia on identity formation. Specifically, we revisit the findings of Clots-Figueras and Masella (2013, The Economic Journal) by examining how exposure to Catalan as medium of instruction affects identity and political preferences. To do so, we use more recent data from repeated cross-sections and multiple alternative sources. Furthermore, we explore an overlooked dimension of identity: self-identification language. At the aggregate level, we find a small but negative effect of bilingual education on the likelihood of identifying as exclusively Catalan. Our results are robust to a battery of sensitivity checks and falsification tests. However, they differ significantly from those of Clots-Figueras and Masella. Our replication of their results reveals a lack of robustness, primarily due to their definitions of identity, as well as to other aspects of their model specification. Our analysis of heterogeneous effects shows that the small negative impact of the reform on identifying as “only Catalan” is entirely driven by individuals from non-Catalan backgrounds, whether in terms of native language or parental origins. For this group, exposure to bilingual education also reduces the likelihood of adopting Catalan as the language of self-identification and support for the independence of Catalonia. These findings suggest that the language-in-education reform might have triggered a backlash effect.