How to avoid dropping schemas when publishing DB in SSDT Database project

When publishing a database from SSDT, there are several options to "do not drop" an object if it is not in the SSDT project. However, it seems that there is no option to avoid dropping schemas. Does anyone know if this is possible to achieve, or do I have to manually edit the published script? This is the problem when I choose to "do not drop tables", but then it will try to drop schemas that have tables in them. br Gert