Boeing plans to suspend production on its 737 Max jetliner in January as the company handles fallout over two deadly crashes that defects in the plane’s anti-stalling system contributed to.

President Trump grounded the plane in March after the second crash. Since then, Boeing has continued to build roughly 40 planes a month at its Washington state factory, according to the Wall Street Journal. The United States’ largest manufacturing exporter now has a backlog of about 400 737 Max planes.