SECTION 1. Section 1 of Chapter 32 is hereby amended by adding at the end of the definition of “wages” the following paragraph:

Notwithstanding the foregoing, wages shall also include payments made by an employer to an employee in supplementation of weekly incapacity payments under the provisions of sections sixty-nine to seventy-five inclusive of chapter one hundred fifty-two, or of sections thirty-four, thirty-four A, thirty-four B, thirty-five A, thirty-five F, thirty-six, until a retirement allowance becomes effective for him under the provisions of sections one to twenty-eight inclusive of this chapter. The extent to which these supplemental payments are considered wages shall be limited, when combined with such incapacity payments, to the amount that in the determination of the retirement board the member would have received during the applicable time period, had they not been so incapacitated.