Dependent issue

Hello everyone,

Background:  my son turned 18 in Sept. of 2021 and he earned just under 12k part time working a few nights per week and on some Saturdays.     He filed his tax return already under the turbo tax free file option.     I told him that he made too much so I would not be able to claim him as a dependent and that is how he filed.         

I just today got my Turbo tax deluxe version E-filed.     Turbo tax never asked me about how much he earned and it allowed me to still claim him as a dependent as I paid for all of his care and well being.     I forgot that he stated that nobody claimed him and now I think I have a problem.

Do I need to amend my tax return to not claim him or does my son now need to amend his return to state that he was claimed by someone else?