Make-up contribution/deduction

[Ervin Barham]

Client discovers participant excluded from profit sharing plan and money purchase pension plan in error and agrees to "make up" the contribution plus earnings under APRSC.

I know the P/S contribution is deductible to the extent there is room under the 15% cap and to the extent that you don't exceed the 25% overall limit between the two plans.

My poor ol' search engine doesn't provide me with the answers I need, so could someone direct me to a cite as to whether the "make-up" earnings are also deductible?

Thanks.