The Duffer Brothers say the Stranger Things season 5 finale was "the most difficult writing circumstance we've ever found ourselves in" because they were "constantly getting hammered" by Netflix

The Duffer Brothers have revealed that the Stranger Things season 5 finale was "the most difficult writing circumstance" they've ever experienced.

"We were getting hammered constantly by production and by Netflix for episode 8," the duo revealed in the new documentary One Last Adventure: The Making of Stranger Things. "It was the most difficult writing circumstance we’ve ever found ourselves in, not just because of the pressure to make sure the script was good, but because there was never so much noise at the same time."

Matt Duffer also admitted that "we went into production without having a finished script for the finale. That was scary because we wanted to get it right. It was the most important script of the season."

The finale to the long-running show has proved unpopular with fans, with some even going as far as to convince themselves that it was a fake-out and an additional, secret episode was on the way to provide a "real" ending for the series (AKA Conformity Gate).

One Last Adventure: The Making of Stranger Things was released on Netflix on January 12 and goes behind the scenes of the hit show's final season – and it features plenty of other interesting reveals, including the fact that the show's ending was changed to make Eleven's fate more ambiguous.

All episodes of Stranger Things are now streaming on Netflix. For more on the final season, check out our Stranger Things season 5 finale review, or our guide to the Stranger Things season 5 finale ending explained.