FOP/PDF: How to keep section title together with following paragraph?

Hi,

I'm trying to get my tool chain to keep section titles together with the
(beginning of the) first paragraph of the section in the resulting PDF. So
far, I have failed to find out what exactly I have to do to accomplish
that. Can anyone give me a hint?

The tool chain consists of:

- DocBook 1.78.1 stylesheets
- Saxon 9.4.0.6
- Apache FOP 1.1

Best regards,
Stefan