The cast of Stranger Things dealt with plenty of adult situations in Season 1, but little that would earn an R-rating. Season 2 may be a different beast, as the Duffers reveal its pint-sized stars are “much more foulmouthed” this time around, and even petitioned Netflix to keep it that way.

The writer-directors spoke to Wired about the new season and the challenges of accommodating its growing stars. Ross Duffer joked that where Gaten Matarazzo resembled “a little muppet” in Season 1, the young cast “are full-on teenagers” heading into Seasons 2 and 3. The second season taking place over the course of a week also contrasts with noticeable growth spurts during production, of which Matt said “You’ll hear changes in their voice, but you can’t do much about puberty. Except maybe shift the pitch.”

Still, with young adults comes adult language so much so that the Duffers were nervous about Netflix’s reaction to the uptick in maturity, until the kids themselves petitioned to leave it in:

ROSS: When Netflix saw the first two episodes, they realized this is fine, it’s not going to turn off families—

MATT: —but first, we actually gave in and took out all of the bad language, and the kids got really upset. Then I wrote Netflix saying I’ve got this army of 11- and 12-year-olds and they’re pissed off that we cut all the language. At least let us shoot alternate takes. That was, like, the day before we started shooting. And then Netflix said OK.

ROSS: They’re much more foulmouthed in season two than in season one, but in real life it’s far worse. I’m like, I cannot believe that came out of your mouth.

We’ll have to wait another week to hear Will, Mike, Eleven, Dustin or Lucas suddenly curse up a storm, but their rapid maturity is exactly why Netflix pushed to shoot Seasons 3 and 4 back to back. In the meantime, check out the latest trailer below, and stay tuned for more on Stranger Things Season 2 before next week’s premiere.

Check Out 100 TV Facts You May Not Know!

More From 92.9 WBUF