The imminent WeChat ban that was set to remove the app from U.S. app stores on Sunday is going to have to wait a bit longer. It's a big positive step for an app that has more than a billion users worldwide.

In a Sunday ruling, a U.S. judge in California put the brakes on Donald Trump's executive order from August calling for a WeChat ban (h/t CNBC). The court decision grew out of a lawsuit filed by the U.S. WeChat Users Alliance, following a Friday hearing.

"This is nothing else than a ban," Alliance attorney Michael Bien said in court on Friday, according to the Wall Street Journal. "What matters is our clients' rights to use the app will end on Sunday," he added, referring the the Sept. 20 date for the ban as laid out in Trump's order.

The executive actions were motivated by what Trump described as a national security risk, with Chinese companies – specifically WeChat and TikTok, in this case – potentially having access to American citizens' user data. The order called for control of the data to be handed over to U.S. interests, and that seems to be happening in the case of TikTok.

In the California WeChat case, the federal government maintained that a WeChat ban didn't represent an infringement on the plaintiffs' constitutional rights because there are other apps that provide similar features. But Judge Laurel Beeler, who is presiding over the case, wasn't sold.

"[T]he court grants the plaintiffs' motion for a preliminary injunction on the ground that the plaintiffs have shown serious questions going to the merits of the First Amendment claim, the balance of hardships tips in the plaintiffs' favor, and the plaintiffs establish sufficiently the other elements for preliminary-injunctive relief," the court order reads.

The injunction also blocks a U.S. Commerce Department order that would have prevented U.S. interests from doing business with WeChat. Such a move could have undermined the platform's performance and functioned as a sort of de facto ban.

Neither Trump nor the Commerce Department had commented on Beeler's decision at the time of this writing. But this is a preliminary injunction meant to avoid unnecessary disruptions while the lawsuit unfolds, so the legal struggle is far from over.