The actress, who plays Eleven in the hit Netflix series, criticised the writers for failing to kill off some of the show's main characters.
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In an interview with TheWrap back in May, she said: "It's way too big. Last night, we couldn't even take one group picture because there was like 50 of us. I was like, 'You need to start killing people off.'
"The Duffer brothers are two sensitive Sallies that don't want to kill anyone off. We need to be Game of Thrones. We need to have the mindset of Game of Thrones.
"They tried killing David [Harbour] off and they brought him back. It's ridiculous," she added.
When the brothers were asked about Millie's comments in the latest edition of the Happy Sad Confused podcast, Matt responded: "I've heard."
Millie plays Eleven on the show
"What did Millie call us? She said we were 'sensitive Sallies'. She's hilarious."
Defending the writers' decision to keep the show's main characters alive, Matt said: "Believe us, we've explored all options in the writing room. The problem is - Just as a complete hypothetical, if you kill Mike, it's depressing... we aren't Game of Thrones. This is Hawkins, it's not Westeros. The show becomes not Stranger Things anymore, because you do have to treat it realistically, right?"
He continued: "So even when Barb dies, there's two seasons worth of grappling with that, so imagine Mike dying - is that something we’re interested in exploring or not interested in exploring? Eddie's death is going to have huge repercussions in season five… Every death has an impact."
Eddie died in the latest instalment of the hit sci-fi drama
He went on to tease that "more deaths" are on the table in season five, before adding: "This is me basically defending myself against these Millie Bobby Brown accusations and explaining that there are lives behind it, and it’s nothing to do with my sensitivity.
"So there you go Millie."
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