Stranger Things season 4 is on track to wrap filming this summer. At this point, we are nearly two years past the release of the hit horror show's third season on Netflix, as Stranger Things season 3 hit the streamer in July 2019. We still have no idea exactly when the next season will finally make its way to Netflix as well, but the good news is that it appears production is almost finished.

This week on Jimmy Kimmel Live, series star David Harbour appeared to help promote the release of Black Widow next month. The subject naturally turned to Stranger Things during the interview and Harbour was asked about the current state of its production. Though he might be crossing a line by volunteering this information, the actor suggested that the end of the shoot is in sight with plans to wrap during the summer.

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"I mean, you're not supposed to say but I'll tell you," Harbour said. "Yeah, I'm almost done. I've got one more, like, little stint. We should be done in, like, August. I gotta shave [my head] again."

Harbour was previously featured in a special sneak peek at Stranger Things 4 released by Netflix. The footage revealed that Harbour's Hopper was still alive, but is being held prisoner in some sort of Russian prison. It also brought about a new look for Hopper, including a shaved head. Apparently, as Harbour explained on Jimmy Kimmel Live, this appearance was a direct result of the actor's role in Black Widow, as he didn't want both characters to look exactly the same.

"I knew that I was going to be in this Russian prison and then literally a month later I got a call from Marvel that they wanted me to play a guy who starts out in a Russian prison," Harbour explained. "I was like, this is fantastic. I can't wait to see what Twitter and Reddit and all those guys do with it. So there's all these conspiracy theories that, like, you know, Hopper went to Russia and then put on a supersuit and now he's the Red Guardian in this Black Widow movie."

David Harbour added: "I kept sending these photos [to the Duffer Brothers]. And then finally at the end, I had all this hair and all this beard and we planned to do it that way and I was like, guys, we can't do this. I'm coming out with this Marvel movie. I can't have the beard and the hair. So we came up with a whole different look for [Hopper]. We had him shave his head and this whole thing."

Another sneak peek clip of Stranger Things 4 teases the return of Millie Bobby Brown as Eleven. Beyond that and the Russian prison clip, there's nothing else that's known about what will happen in the new season. Gaten Matarazzo has also teased that it will be the scariest season yet.

The release date for Stranger Things 4 has yet to be revealed, but the first three seasons can be binged on Netflix. Harbour can also be seen on the big screen when Black Widow is released on July 9. This information comes to us from Jimmy Kimmel Live.