David Drummond, chief legal officer at Alphabet Inc (NASDAQ:GOOGL) has given up his director position at Uber’s board due to conflicting views over self-driving vehicles. This is the latest development in the Uber rivalry with Google.

Drummond’s exit from the board comes at a time when there is increasing rivalry between Alphabetd an Uber. Drummond has been on the board of Uber for the past three years but his tenure as a board member for the firm ended on Monday. His exit comes just a few days after the company’s CEO Travis Kalanick announced a partnership with Otto, a company with autonomous trucks. The announcement was also part of Uber’s acquisition of Otto. The acquisition of the latter came with a $300 million deal through which Uber and Volvo will develop self-driving cars.

Uber and Alphabet were partners not long ago but somewhere along the line they had a falling out and their partnership devolved into a rivalry. The two companies are now competing for the same space in the rapidly growing autonomous vehicle space which was pioneered by Google a few years ago. Drummond released a statement on Monday claiming that the rivalry between the two firms had a lot to do with his departure. He also expressed good sentiments towards Uber, describing it as a phenomenal firm.

Kalanick expressed his gratitude to Drummond through a statement and also stated that he looks forward to working together with Google. Uber has been trying to gain more ground in the self-driving vehicle industry and is making acquisitions that it believes will strengthen its position in the future. The company wants to be at the forefront of the technology revolution. A few weeks ago, the company’s CEO announced that Uber plans to launch the first fleet of driverless vehicles in Pittsburgh.

Uber’s new fleet will include roughly 100 modified Volvo XC90 vehicles. The testing will include an engineer in each of the vehicles to monitor the performance and take over in case of any problems.