Game of Thrones” writers David Benioff and Dan Weiss are looking back on one of the biggest gaffs of the series.

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A coffee cup infamously appeared on a table in the background during the episode “The Last of the Starks”, which aired during the show’s final season.

Although the cup has since been removed from the episode, the mistake resulted in a lot of hilarious memes.

In James Hibberd’s “Game of Thrones” series-chronicling book, Fire Cannot Kill a Dragon, Benioff and Weiss reflect on the regrettable incident.

“I couldn’t believe it,” says Benioff, according to The Hollywood Reporter.

“When we got the email about it the next day, I honestly thought someone was pranking us, because there had been things before where people were like, ‘Oh, look at that plane in the background!’ and somebody had Photoshopped it in. I thought, There’s no way there’s a coffee cup in there. Then when I saw it on the TV I was like, ‘How did I not see that?’”

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Weiss added, “I’d seen that shot one thousand times, and we’re always looking at their faces or how the shot sat with the shots on either side of it…. Every production that’s ever existed had things like this. You can see a crew member in ‘Braveheart’; there’s an actor wearing a wristwatch in ‘Spartacus’. But now people can rewind things and everybody is talking to each other in real time. So one person saw the coffee cup, rewound it, and then everybody did.”

Fire Cannot Kill a Dragon is available from Oct. 6.

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The ‘Game Of Thrones’ Cast Then And Now