Painting matt emulsion over oil-based eggshell?

[bitebitebite]

My hall walls are painted in F&B oil-based egg because it was extra durable. It's been fantastic, I've been able to scrub it clean when needed. But that was 10yrs ago... Now I want to repaint, probably in a regular matt paint. Will the matt adhere to the oil-based egg or will I need to somehow 'prime' the wall?

That sounds like a difficult one. Have a look at www.diynot.com and go to the Decorating and Painting forum, there are loads of people there who know about such things