Lookalike KitKats could start flooding the market, following an EU ruling that the chocolate bar's iconic four-fingered shape can't be copyrighted.
After a long legal battle with rival Cadbury, Nestle has been told by the advocate general of the European court of justice that its attempts to trademark the KitKat shape in the UK fall foul of EU law.
If, as is expected, the decision is adopted by the EU court, it could open the door for copycat chocolate bars that snap into four separate fingers.
In theory, it's possible to trademark the shape of a chocolate bar - Toblerone, for example, has managed it. But shapes are harder to trademark than, say, logos or names, as the manufacturer has to demonstrate that it's distinctive enough for a consumer to use it for identification.
Even Nestle's attempt to trademark the shape of the Polo mint failed on these grounds - "An appeal with a hole in the middle," commented the judge.
Now, rival manufacturers have carte blanche to copy the famous design - just as toy makers did when Lego was refused copyright on the shape of its bricks in 2010.
The design of the KitKat has hardly changed since the bar was launched in 1935, and is certainly very characteristic. In court, Nestle pointed to research showing that 90% of people recognised a KitKat without its wrapper or any branding.
However, the advocate ruled, it's simply not distinctive enough to be trademarked separately from its brand name and packaging.
"It seems that the old 'elephant test' isn't enough for trademark lawyers," comments Iain Connor, intellectual property lawyer at Pinsent Masons.
"Despite the fact that consumers know a KitKat when they see one, the advocate general has said that the court needs to see evidence of a level of acquired distinctiveness way beyond 'mere recognition'."
It's hard not to see the lawsuit as a bit of tit-for-tat retaliation: Nestle had previously blocked Cadbury from trademarking the particular shade of purple that it uses on its Dairy Milk wrappers. That case came to an end in 2013 - and Cadbury challenged Nestle over the KitKat soon after.
The chances are that Cadbury itself won't attempt to copy the KitKat. More likely are own-brand versions, particularly from discounters such as Aldi or Lidl. Anyone for a KatKit?