Aldrin, 88, tweeted out a picture of the flag planted after the landing in 1969.
The famous astronaut was the second man to step on the moon after Armstrong but it appears he isn't happy with Ryan Gosling's new movie.
He captioned the photo: 'Proud to be an American.'
Aldrin also re-tweeted a photo of him saluting next to the same picture.
The film chronicles Neil Armstrong's life from 1961 to the Moon landing in 1969 – but critics noted it leaves out the moment Armstrong plants a American flag on the moon.
It appears Aldrin is taking a very public dig at director Damian Chazelle's controversial decision not to include the planting of the flag at the end the movie that opened the Venice Film Festival on Wednesday.
To make matters worse the film is not that kind to Aldrin either with Corey Stoll's performance showing him as an 'obnoxious loudmouth' and 'so blunt about his ambition that no one can stand him.'
'First Man' is being tipped to win big at the Oscars receiving rave reviews from critics.
While Gosling has defended the decision not to show the flag planting – claiming the achievement 'transcended countries and borders.'
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