An overdue book was returned to a library in Scotland nearly four decades after it was initially checked out.

Shetland library shared a photo of the book that was borrowed on Oct. 10, 1981, 36 years before it was finally returned.

"We're always delighted when customers return our library books, having enjoyed them and looked after them like they were one of their own collection," the library said. "This naughty little book was so well-looked after, he didn't want to come back!"

Karen Fraser, executive manager of library services, said the 1961 copy of Highland Folk Ways by I. F. Grant was "well thumbed" but in excellent condition.

The customer said she was slightly embarrassed to return the long overdue book, which she discovered while cleaning her home.

"It's really good that customers are honest and bring the books back," Catherine Jeromson, senior library assistant, said. "That [one] was in pristine condition and it could've been borrowed the previous week rather than being borrowed for 36 years."

The book was returned free of charge, as the library doesn't collect fines and Jeromson said anyone with a severely overdue book can easily return it without judgement.

"If anybody's too embarrassed to say to our face 'I'm really sorry I've had this for 30-odd years' they can put it in the returns bin outside," she said.