Japanese auto giant Toyota Motor is investing $500 million in Joby Aviation to support the U.S. electric air taxi company’s launch of commercial passenger services, which are slated to begin as soon as next year.

The investment comes at a time when Joby is ramping up production for its five-seat electric air taxis. Toyota is now Joby's lead investor.

Toyota, an existing Joby partner, apparently likes the progress Joby is making. The automaker has agreed to invest an additional $500 million through the purchase of two equal tranches of Joby stock, with the first expected to close later this year and the second in 2025.