Amazon is being judged by this book cover.

Author and design critic Mike Monteiro is using a revised cover for his recently-released book, “Ruined by Design” — published on Amazon’s independent publishing platform — to convince the company’s warehouse employees to form a labor union.

Monteiro created a new cover for his book — which has nothing to do with labor unions — that is emblazoned with the words “ATTENTION AMAZON WORKERS” and informs them that they have the right “to decent working conditions,” “to bargain collectively” and “to form a union.”

Between their 12-hour workdays and lack of bathroom breaks, Amazon staffers may not have much time to consider unionizing, which might ensure better working conditions. But Monteiro’s hope is that employees will see the message as they pack and ship the book for delivery.

“Every time you buy my book from Amazon, a warehouse worker has to pull it off the shelf. From now on, this is what that worker will see. At least until Amazon s–tcans the whole thing. Hurry up,” tweeted Monteiro on Friday.

He told The Verge he had decided to pull the prank after discovering he could change the jacket of his $22.49 book by uploading a revised PDF version for Amazon’s book printers. He added that the new cover had already been put through one of the retailer’s quality assurance processes and that Amazon has not reached out to him at this point. However, the company reportedly told The Verge that the cover doesn’t violate its guidelines.

Though he’s sold 10,000 books overall, the new jacket will appear only on the book’s latest paperback version, which has sold just 150 copies so far.

Monteiro said he’d been researching how unions are organized when he came up with the idea.

“We were discussing how to get messages in front of people and I realized ‘Oh, huh. I have this thing that Amazon workers see every time a book gets ordered. Let’s put a message there,’ ” he says.

In a statement to The Post, a rep for Amazon says employees work 10-hour days, workers are allowed to use restrooms “whenever needed” and “benefits and opportunities come with the job.”

“The fact is that Amazon already offers what unions urge employees to request,” says the representative. “We encourage anyone to compare our overall pay, benefits, and workplace environment to other retailers and major employers in the community and across the country.”