Things might get rough for Samsung in its U.S. patent fight against Apple.

In a ruling earlier this week, Apple won an appeal in its district court fight against Samsung to move for a preliminary injunction against the sale of Samsung’s Galaxy Tab 10.1 and some of the Korean device maker’s smartphones because of alleged patent infringement. Samsung and Apple have been hammering it out in courts all over the world over patent issues, and Apple has even won a few injunctions against the company. Those injunctions can halt the sale of Samsung’s devices, and a preliminary injunction in the U.S. would do the same.

Apple lost a motion back in February for a preliminary injunction against Samsung, when a judge ruled that Apple hadn’t proven that it would be irreparably harmed by Samsung continuing to sell its products in the U.S. As The Wall Street Journal reports, however, Apple appealed the ruling and the Court of Appeals for the Federal Circuit has ruled in Apple’s favor. That leaves Apple free to attempt to get the sale of Samsung’s devices banned from the whole country for patent infringement.

Of course, nothing is set yet, and Samsung isn’t banned from selling its products. Apple has only won the right to make its case again. It’ll now go back to the district court and make a case for why Samsung’s designs infringe on its patents, and what’s more, how those infringements hurt Apple’s business. If it makes a decent case, the court can issue a preliminary injunction banning Samsung’s devices temporarily while it makes its final ruling about whether patents have been violated. The same thing happened to Samsung in a few of its cases with Apple in Europe and Australia.

Last time around, the district court ruled that Apple’s claims that Samsung infringed on its design patents for the iPad and iPhone were actually obvious designs, given that other devices created before Apple’s also included similar elements, like the single piece of glass for the iPad’s face and its bezel style. That Samsung uses those elements as well, it ruled, didn’t infringe on Apple’s designs.

But the Court of Appeals ruled that the differences between Apple’s design and others were enough that its patent was non-obvious, or sufficiently unique that Samsung could infringe upon it. That means, basically, that Apple does have a design patent and that Samsung can infringe on it. For the injunction, Apple now has to prove that it’s being irreparably harmed by Samsung during the period in which the judge is ruling on those patents.

That might not be an easy thing to prove, but Apple has cleared a big hurdle. Samsung has suffered these injunctions before, but the financial pain would definitely be worse in the U.S., where it’s currently the top smartphone maker. Either way, the legal battle is set to continue for quite a while into the future.