So far energy system models only consider labour markets ex-post to showcase the employment possibilities which a energy transformation can provide. Given the demographic changes in Europe, labour markets will decrease and continue to create scarcities in some sectors. In future, labour markets could become a bottleneck for the transformation and determine its shape and speed. To account for that, we integrate labour markets in the optimization rather than only consider it ex-post. Results indicate a increasing energy import dependency when labour market constraints are considered.