Pay slightly decreased due to entering higher tax bracket - do I need to let mortgage advisor know?

I have a mortgage offer and my mortgage advisor told me to let them know if there is any changes that could affect the mortgage. My pay is down about £100 due to entering the 40% tax bracket so is that the sort of thing I need let them know?

I would like to think the mortgage lender would think about that before issuing an offer but you never know!