There was briefly cross-platform play in Fortnite between users on Xbox One and PlayStation 4, over the weekend, Epic Games confirmed today.

Gamers in the Fortnite subreddit spotted what they thought was cross-console play in the co-op sandbox survival game over the weekend. While others were skeptical that Xbox One users and PlayStation 4 users were in fact playing together (thinking someone had mistaken a PC gamertag for an Xbox Live handle), an Epic representative said this afternoon that that’s exactly what was happening.

“We had a configuration issue and it has now been corrected,” the spokesperson said.

This is unusual because, while Microsoft opened the Xbox platform to cross-platform play last year beginning with Rocket League, Sony has been resistant to letting PlayStation 4 gamers share an ecosystem with Xbox One.

This June, Psyonix, the makers of Rocket League, said that cross platform play between the Xbox One and PlayStation 4 was feasible but “PlayStation has not yet granted us permission.” Sony later ruled out cross-platform play with Minecraft on the Xbox One as well. A top executive implied that Sony was against it because the company couldn’t assure the online safety of its customers playing with users moderated by another platform. Xbox head Phil Spencer rejected that explanation. “I don’t know why that has to become the dialogue,” he said. “Like, that doesn’t seem healthy for anyone.”

The users who noticed the cross platform play uploaded screenshots of the different gamertags (PlayStation Network accounts cannot have spaces in them), and then a father-and-son duo posted a picture of them playing Fortnite side-by-side on the two consoles.

Sony did not respond to a request for comment, but judging from the one Epic made, it sounds like cross-platform play won’t be coming back to Fortnite.

Update: Xbox head Phil Spencer continues to advocate for opening up consoles to cross-platform play. Asked by a Twitter user for his thoughts on the temporary availability of PS4/Xbox One play in Fortnite, after Epic shut off the feature, Spencer replied, “I would have liked to see them leave it on.”