Amazon (AMZN) is looking to sell a significant portion of the ad space on Walt Disney’s (DIS) apps, but Disney has so far resisted, raising the risk that Amazon’s Fire TV will be the only major streaming platform that will not offer the DIsney+ service on its Nov. 12 launch, The Wall Street Journal reported on Thursday.

If the two companies do not come to an agreement, Disney may also see its apps removed from Fire TV, including ESPN+. That would be an unwelcome development for Disney. Fire TV is the second largest distributor of streaming apps. Disney, entering the streaming video market , will compete with the likes of Netflix (NFLX) for popularity.

Some sources told The Wall Street Journal that there is optimism that Amazon and Disney will reach an agreement, with no deadline on when talks will need to close.