The Simpson producer reveals a big mistake of the series

There is an error in The Simpsons that even the most hardcore fans have missed.

In Season Six Episode 13, when Marge tells Homer that she's pregnant with Maggie, Maggie's picture already seems to be framed on the wall behind them.

Executive producer Matt Selman tweeted the error of "And Maggie Makes Three" to fans yesterday.

While some argue that the picture is of Lisa, not Maggie, others say that the show has predicted the future.

It seems that Matt is not the only person working on the series who did not realize the mistake.

Al Jean, another writer on The Simpsons, did not seem to have tweeted either: "Canon is in ruins!"

And Yeardley Smith, who is Lisa Simpson's voice, tweeted: "Oops".

Fans of the show hastened to share their thoughts on the omission, with some claiming that "the obvious excuse" is that the photo is actually that of Little Lisa.

Others insist that the series has predicted the future, a popular theory of the Simpsons since fans claimed that Donald Trump would become president of the United States in 2000.

Fans also discovered that the show predicted the takeover of 21st Century Fox by Disney 19 years before it would happen.

But Maggie's mistake is not the only continuity error on the series.

Some pointed out that a similar situation had occurred when Marge had told Homer that she was pregnant with Lisa.

He passes in front of a picture of their daughter while she is not even born yet.

Others have spotted that an episode where Lisa is a baby includes a picture of her as a child already framed on the wall.

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