Painting over peeling paint

[finlamit]

I am painting a bathroom a new colour. The paint in not in terrible condition apart from a few areas that have peeled. See image.

Looking under the peeled paint it looks like a mist coat was never applied to the freshly plastered walls. Instead the top coat was added on-top of the plaster, therefore causing it to flake off.

Any advice on what should be done here. I thought of scraping as much off the peeling areas as possible then applying some Zinsser Peel stop on top, then going over the entirety of the existing paint with a primer then top coat. Does that seem ok? If so, any primer/undercoat recommendations?

Thanks

M