Back in December, Judge Lucy Koh refused to give Apple the sales bans it wanted on 26 Samsung products found to infringe on its patents, ruling that Apple needed to establish that the patented features were "important drivers" of demand for the offending devices. Now Apple is appealing the ruling, arguing that it sets the bar too high, and it’s getting help from an unlikely friend — Nokia. The Finnish cellphone maker filed an amicus curiae brief in support of Apple this week, and while the filing is under seal, Nokia outlines its position clearly in an accompanying motion.

Nokia argues that the ruling would create a compulsory licensing system

The company argues for patent laws as a means of developing technology for public benefit, but also supports permanent injunctions against infringing products "in appropriate circumstances." It asserts that Judge Koh’s requirement for a "causal nexus" would cause "wide-ranging damage to the United States patent protection landscape," adding that the ruling makes the standard for getting an injunction so hard to reach that "it may rarely, if ever be met." Nokia argues that the ruling would create a compulsory licensing system, hurting incentives to innovate.

In its introduction, Nokia points out that it’s got skin in the patent game, both as a patent owner that could potentially want sales bans against other companies, and as a manufacturer that could be on the receiving end of similar litigation. Nokia is the only company to file an amicus brief on Apple’s behalf, made all the more interesting by the two companies’ own 2009 patent battle.