An eagle-eyed Harry Potter fan has taken to social media to share the hilarious moment that the lead cast members are replaced by random actors in the Prisoner of Azkaban.
Despite being released almost 20 years ago in 2004, until now, this glaring error has never been public knowledge.
Taking to TikTok, user @ocarroll pointed out the very brief moment where all of the movie's leading actors are replaced by random people - an observation which, at the time of writing, has been viewed over half a million times.
Watch the previously unnoticed replacement below:The video begins with @ocarroll stating that she has watched the film too much, before showing her surprise at the realization that in one scene, each of the lead actors are replaced by random body doubles.
After showing the moments that Harry, Hermione, Ron, and Professor Lupin are all replaced by random body doubles, the TikTok user simply says that she doesn't know what to do with this information.
The replacements all took place within the scene where Harry must confront a Boggart during Professor Lupin's Defense Against the Dark Arts class.
While the use of body doubles to replace such famous faces might seem surprising, as per Insider, it's actually quite a common practice when lead actors are in the background of scenes - as is the case here.
Needless to say, body doubles are also commonly used in high-action scenes and in those involving nudity.
One commentator joked in response to the video: "Harry and Hermionie from Wish."
A second added: "I've always thought that it was random students from class, never realized it was supposed to be Harry."
Meanwhile, a third shared: "My friend was one of the doubles of Harry in the last two films."
The use of body doubles not only saves money, but time, and it is in compliance with The Screen Actors Guild's union rules, which state that the lead actors must have 12 hours rest between when shooting wraps up one day and begins the next.
This is what is known as "turnaround time", and the use of body doubles means that scenes can still wrap on the same day even if the lead actors are no longer able to work.