Toyota Motor Corporation will invest $500 million in Uber to work in conjunction on developing self-driving cars, a bid by both companies to catch up to rivals in the highly competitive autonomous driving business.

Toyota, one of the world’s largest carmakers, and Uber Technologies Inc, the leading ride-hailing service, are widely seen as lagging the competition in developing self-driving cars. The partnership deepens an existing relationship and reflects CEO Dara Khosrowshahi’s strategy of Uber developing autonomous vehicles through partnerships, rather than on its own.

The investment values Uber at $72 billion, matching the valuation Uber received in a deal with Alphabet Inc (GOOGL.O) self-driving unit Waymo this year.

Uber will combine its autonomous driving system with Toyota’s Guardian technology, which offers automated safety features such as lane-keeping but does not enable a vehicle to drive completely autonomously. The combined technology will be built into Toyota’s Sienna minivans, to be deployed on Uber’s ride-hailing network starting in 2021.

Previously, Uber and Toyota partnered on an electric mobility project. Two years ago, Toyota invested an undisclosed sum in Uber and the two companies partnered on a car-leasing program for Uber drivers. Uber has since shuttered its U.S. leasing business.