The Supreme Court on Wednesday said it will hear arguments next month over the constitutionality of the federal law that could ban TikTok in the United States if its Chinese parent company doesn’t sell it.

The justices will hear arguments Jan. 10 about whether the law impermissibly restricts speech in violation of the First Amendment.

The law, enacted in April, set a Jan. 19 deadline for TikTok to be sold or else face a ban in the United States. The popular social media platform has more than 170 million users in the U.S.

It’s unclear how quickly a decision might come. But the high court still could act after the arguments to keep the law from taking effect pending a final ruling, if at least five of the nine justices think it’s unconstitutional.

Lawyers for the company and China-based ByteDance had urged the justices to step in before Jan. 19. The high court also will hear arguments from content creators who rely on the platform for income and some TikTok users.

The timing of the arguments means that the outgoing Biden administration’s Justice Department will make the case in defense of the law that passed Congress with bipartisan support and was signed by Democratic President Joe Biden in April.

The incoming Republican administration might not have the same view of the law.

President-elect Donald Trump, who once supported a ban but then pledged during the campaign to “save TikTok,” has said his administration would take a look at the situation. Trump met with TikTok CEO Shou Zi Chew at Trump’s Mar-a-Lago club in Florida on Monday.

The companies have said that a shutdown lasting just a month would cause TikTok to lose about one-third of its daily users in the U.S. and significant advertising revenue.

The case pits free speech rights against the government’s stated aims of protecting national security, while raising novel issues about social media platforms.

“We believe the Court will find the TikTok ban unconstitutional so the over 170 million Americans on our platform can continue to exercise their free speech rights,” TikTok spokesman Michael Hughes said in a statement.

Free-speech advocates also praised the court’s decision to step in.

The government should not be able to restrict speech “without proving with evidence that the tools are presently seriously harmful. But in this case, Congress has required and the DC Circuit approved TikTok’s forced divestiture based only upon fears of future potential harm. This greatly lowers well-established standards for restricting freedom of speech in the U.S.,” David Greene, a lawyer with the Electronic Frontier Foundation, said in a statement.

A panel of federal judges on the U.S. Court of Appeals for the District of Columbia Circuit unanimously upheld the law on Dec. 6, then denied an emergency plea to delay the law’s implementation.

Without court action, the law would take effect Jan. 19 and expose app stores that offer TikTok and internet hosting services that support it to potential fines.