Lucid Group is cutting its car production forecast for this year by as much as 40%, sending shares of the electric vehicle start-up tumbling 13% during after hours trading.

The company on Monday cited supply chain constraints and parts quality issues for slashing production to between 12,000 and 14,000 vehicles, down from initial expectations of 20,000.

“This reflects the extraordinary supply chain and logistics challenges we’ve encountered and our unrelenting focus on delivering the highest-quality products,” Lucid CEO Peter Rawlinson said in a statement. “We remain confident in our ability to capture the tremendous opportunities ahead given our technology leadership and strong demand for our cars.”

The company’s first electric vehicle is called the Lucid Air sedan. Since beginning retail production in the fall, the company has produced more than 400 of the vehicles at a new factory in Arizona. It has delivered more than 300 of those units to customers, including 125 units during the fourth quarter, the company said Monday.

Shares of Lucid, which went public in July through a SPAC deal, closed Monday at $28.98 a share, up by 10%. The company’s market cap is $47.7 billion.

This is a developing story. Check back for updates.