The shares of Rivian AutomotiveAfter a report by the Wall Street JournalAn upstart maker of electric vehicles is now suing its key supplier to delay orders for vans. Amazon.

Amazon placed a large order last year for 100,000 electric delivery vehicles.

According to the report Rivian’s suit accuses Ohio-based Commercial Vehicle GroupIt was accused of breaking its contract with Rivian for seats to be supplied by raising prices sharply after it signed the contract. The Journal reported that it stated in court filings, that the dispute might affect its ability to deliver vans as promised.

According to the report Commercial Vehicle Group denied these allegations. It argued that it was not required to supply the seats at a lower price, and that its price rose after Rivian made changes to the seat design.

Mid-afternoon trading saw Rivian shares fall by about 6% Representatives of Rivian as well Commercial Vehicle didn’t immediately respond to our request for comment.

The full report is available at the Wall Street Journal.