Apple Inc said on Wednesday it plans to lay off 190 employees in its self-driving car program, Project Titan.

Apple said in a filing with California regulators that it plans to lay off people from Santa Clara facilities near its Cupertino, California, headquarters. The reductions, first reported by CNBC, take effect on April 16. A company spokesman confirmed that the reduction is from its self-driving car program.

More than 150 engineers and related fields were among those laid off, according to a letter sent by Apple to California employment regulators. Among those employees, at least two dozen were software engineers and 40 were hardware engineers, according to the letter. At least three product design engineers, one ergonomics engineer and one machine learning engineer were also included in the reduction.

The San Francisco Chronicle first reported the breakdown of the layoffs.

The layoffs appear to be the first major shake-up of Project Titan under Doug Field, who returned to Apple last year after a stint at electric car maker Tesla Inc.