The highest German court ruled on Wednesday that the country’s parliament does not have the power to levy a tax on nuclear fuel, welcome news for the country’s troubled energy companies.

Nuclear power operators RWE, Eon and EnBW will be able to claim billions of euros in refunds from the taxes, levied from 2011 to 2016.

Eon traded up 4.20%, and RWE up 2.28% on Thursday. Eon expects the ruling to result in a refund of 3.3 billion euros, which they said could be used to “strengthen [its] balance sheet” according to the Financial Times.