The aim of the paper is to discuss CLIL and non-CLIL teachers’ language fossilisation in terms of speaking. Firstly, there is a brief overview of fossilisation, focusing on its definition and scope. Secondly, the spoken discourse of CLIL and non-CLIL teachers in the classroom is described. Thirdly, there is a discussion of current research and the data collected through a questionnaire conducted among CLIL and non-CLIL teachers in Poland. This shows that slight differences in terms of language repertoire have been found between CLIL and non-CLIL teachers, placing the former at the forefront due to the strategies they tend to use frequently and the language areas they do not consider to be difficult or problematic at all.