Wing, the drone delivery arm of Google parent Alphabet, and Serve Robotics are joining forces in a pilot partnership.

A new joint venture between Uber’s Serve Robotics sidewalk delivery drones and Alphabet’s Wing flying drone service will do a dual test run. Both tech companies hope that flying and sidewalk drones can cover areas its counterpart can’t and speed up delivery times.

Drones and sidewalk delivery robots promise to make last-mile delivery cheaper and more efficient, but they both have their limitations. Uber-backed Serve Robotics and Alphabet’s Wing are betting that combining forces might just create the ultimate automated last-mile delivery service.