Disney and Amazon are going to war over streaming, according to a report.

The dispute between the corporate behemoths over advertising could impact the future residence of Disney apps on Amazon’s Fire TV as well as distribution for the upcoming streaming service Disney+, according to a story in The Wall Street Journal.

Amazon wants the right to sell a substantial chunk of the ad space on Disney apps, a demand that Disney has so far resisted, the WSJ said, citing people familiar with the situation.

Fire TV is the second-largest distributor of streaming TV apps, including Disney’s, for ABC, ESPN and Disney Channel.

Disney+ is slated to launch November 12. It will cost $6.99 a month and include content from across Disney, Pixar, Marvel and Star Wars.

The WSJ said Amazon often starts out asking for around 40 percent of the ad inventory from programmers and negotiations often bring it down from there.

But well-known apps have leverage and Disney believes its popular apps and the coming launch of Disney+ give it clout. Recently, the two sides have discussed a proposal in which Disney would give up 10% of its ad inventory, according to sources cited by the WSJ.