Valve has been compelled by a California court to provide sales data on more than 400 Steam games to Apple and possibly reveal its yearly sales, revenue, and profits to Apple as well. The iPhone maker subpoenaed Valve for the data as part of its ongoing dispute with Fortnite developer Epic Games.

According to a Wednesday order by Judge Thomas Hixson, Valve will have to provide yearly sales and pricing data on 436 games that are available on both its PC game distribution platform, Steam, and the Epic Games Store. Apple has requested the data so it can define the video game market in its case against Epic.

In a filing published on February 18th, Valve had argued that Apple’s demands were overly broad. Apple had asked for even more data in its subpoena, including annual revenues from Steam, the name of every app on Steam, and the date range for when those apps had been available. Valve argued that the demands would “impose an extraordinary burden” on the company.

Valve has also been compelled to share “aggregated data” about how much it makes from Steam, though it’s not clear exactly what that will entail. Apple had asked for the following:

RFP 2 asks for documents sufficient to show since 2008 Valve’s (a) total yearly sales from apps and in-app purchases from Steam, (b) annual advertising revenue attributable to Steam, (c) annual sales of external products attributable to Steam, (d) annual revenues from Steam, and (e) annual earnings, income or profits from Steam. Apple asks for this information by app if that is available. During meet and confer Apple limited the relevant time period to 2015 to the present.

In his ruling, Judge Hixson largely sided with Apple. “In the letter brief, Valve said this would be an overwhelming amount of work, but other than using adjectives, it did not substantiate or quantify the burden in any way,” Hixson said.

“Apple has shown that it has a substantial need for this information to obtain evidence in support of its arguments concerning market definition and the effects of competition, and it cannot obtain this information elsewhere without undue burden,” he added. “Valve offers several reasons why Apple has not satisfied this standard, but none is persuasive.” Valve is the biggest PC game store in existence and generally doesn’t provide any sales data whatsoever, though you can find simple unordered lists of the bestselling games each month.

Hixson did narrow the amount of information Valve has to provide. While Apple requested data dating back to 2015, Hixson ruled that Valve only needs to produce data from 2017 to the present.

Epic sued Apple in August after Apple removed Fortnite from the App Store for introducing an in-app payment system that it says violated App Store rules.