This paper investigates how bilingual Upper Sorbian-German teachers who belong to the Sorbian speech community (Lusatia, Germany) introduce the minority language during German language lessons in an Upper Sorbian school. In Lusatia, as well as in Sorbian schools, bilingualism is not of equal character; minority language speakers are all bilingual while the German language speakers are not encouraged to speak Sorbian. The language policy of Upper Lusatia gives Sorbs the right to use their language in public life in principle but due to the strained Sorbian-German relations, language ideologies, and hostile attitudes towards the use of minority language in the presence of Germans Sorbs do not benefit from it in practice. The school language policy divides Sorbian-speakers from pupils of German-speaking families and keeps the teaching of Sorbian separate for both groups. Only during the last two years of school are all language groups mixed. Based on participant observation of and in-depth interviews with bilingual teachers during lessons with students of the 11th grade in one Upper Sorbian school this article discusses how teachers negotiate top-down language policy in their classrooms and, introduce bilingualism; and how their language choices affect students' language practices.