Amazon may be shopping for planes to build out its own overnight shipping service

Amazon $AMZN, one of the world’s largest package shippers, may be planning to reduce its dependence on FedEx $FDX, UPS, and the US Postal Service with its own overnight freight service.

The e-commerce giant, which continues to ramp up its logistics investments, is reportedly building out its own US air operation, including potentially buying “perhaps 20” large 767 freighter jets from Boeing $BA, according to Cargo Facts. (Amazon wouldn’t likely operate the actual flying, but would control the operation.)

In November, Motherboard reported on a secretive 767 air-cargo operation in Ohio, codenamed Aerosmith, “shipping consumer goods for a mysterious client that many believe to be Amazon.” Amazon is also reportedly testing a trial air operation in Seattle.

This sort of move, while costly, would match Amazon’s ambitions. While the company obsessed for years over tax-free commerce—which required minimizing its physical footprint—it has recently expanded its distribution network to prioritize delivery speed. It has also moved aggressively into logistics, from warehouse robotics to teasing drone-based package delivery.

Amazon wouldn’t be able to quickly match its current partners’ large domestic and global delivery networks, but it’s not hard to see potential benefits of controlling more of its core distribution infrastructure.

Amazon did not immediately reply to a request for comment.