(NEXSTAR) – A library patron in Minnesota has returned an overdue book 47 years after checking it out, claiming to have forgotten all about it after moving from the area.

Perhaps wisely, the borrower also returned the book anonymously, through the mail, thereby avoiding the disapproving glare of any librarians at the front desk.

The book — “Chilton’s Foreign Car Repair Manual” — was checked out from the Lake Elmo location of the Washington County Library in 1975, the library wrote on Facebook. Upon opening the book, staffers also found a letter of explanation and an apology to the staff.

“In the mid-1970s, I was living in [Lake Elmo] and was working on an old Mercedes Benz,” the borrower explained. “I took out this book for reference. A few months later I moved and apparently, the book got packed up in the move. Forty-seven years later I found it … in a trunk with other interesting things from the ‘70s. It’s a little overdue but I thought you might want it back.

“My apologies to anyone in Lake Elm who was working on an old Benz in the last 47 years. I probably can’t afford the overdue charge but I will send you enough for a new book,” the borrower wrote.

The library confirmed the package did indeed come with a donation. The borrower, however, was off the hook for any library fees, as the library no longer charges any.

“We haven’t had daily fines for overdue materials for a long time, but we do still charge a replacement fee if an item is lost or damaged,” the library said in response to a Facebook user who asked about the policy.

“We’re just glad to have the book back,” read the Facebook post.