If it is a normal incremental increase you are fine - it is your pensionable salary.
"Pensionable salary is, generally, the annual salary of an officer on the last day of
established service.
Effective from 20 December 2001, if an officer is worksharing,
pensionable salary is based on the salary which would be payable if the officer was
working in a full-time capacity1. Moreover, if any officer has had a change in grade or
has received a personal change in salary - other than a general or grade increase or
normal increments - within 3 years of the retirement date, his/her salary is averaged in
calculating pensionable salary."
If it was due to a promotion, acting up, etc. it would be different.