San Francisco Giants reliever Jeremy Affeldt is revealing how he returned $500,000 to the team following a contract snafu.

According to The San Francisco Chronicle, in his book ‘To Stir a Moment,’Affeldt details how he and team officials agreed on a $4 million contract in 2010, but once the paperwork was actually drawn up the amount written read $4.5 million. Both sides agreed to the terms without noticing the error.

Later, when Affeldt noticed the discrepancy, he alerted team officials, who begrudgingly informed him the team was now liable for the amount actually stipulated on the contract. It was then that Affeldt moved to return the extra money.

“I talked to Bobby Evans the next day,” Affeldt writes in his novel about subsequent meetings with the team’s assistant general manager “’I said I can’t take that money. I won’t sleep well at night knowing I took that money because every time I open my paycheck I’ll know it’s not right.’”

Affeldt’s agent, Michael Moye, and numerous MLB executives also assured him that he was within his rights to keep the money. But by then, his mind was already made up.

Not to worry, Affeldt’s honorable act has not gone unrewarded. He’s since signed a three-year deal with the defending World Series champs for some $18 million.