Having already stabbed Uber by way of a potentially disastrous lawsuit, Waymo is now twisting the knife.

The Google spinoff says it will partner with Lyft, Uber?s biggest ride-hailing rival, to help test and launch self-driving cars.

Having access to this new technology would be a big coup for Lyft, as Waymo?s self-driving efforts are ? quite literally ? miles ahead of the pack. Waymo announced last month that it plans to add 500 self-driving cars to its fleet, and the vehicles are improving as they come online.

Compared to Waymo ? and Uber, which has an entire division dedicated to autonomous research ? Lyft?s efforts on self-driving vehicles are badly lagging. The company partnered with GM early last year, but isn?t ready to test a fleet. It only has a few GM research vehicles (for now).

Both Lyft and Waymo confirmed to HuffPost the news of their partnership, although neither company could share details about the deal ? which comes at a curious time. Waymo is currently engaged in a fierce legal battle with Uber, as it has accused the company of stealing the self-driving technology it?s now sharing with Lyft.

?We?re looking forward to working with Lyft to explore new self-driving products that will make our roads safer and transportation more accessible,? a Waymo spokeswoman told HuffPost. ?Lyft?s vision and commitment to improving the way cities move will help Waymo?s self-driving technology reach more people, in more places.?

Lyft has a history of teaming up with Uber?s rivals, albeit with limited success. In 2015, it partnered with the Chinese ride-hailing company Didi Chuxing while Uber attempted to make inroads in the country. The partnership skidded to a halt last summer, however, after Uber agreed to sell its Chinese operations and take an ownership stake in Didi.

– This feed and its contents are the property of The Huffington Post, and use is subject to our terms. It may be used for personal consumption, but may not be distributed on a website.