Boeing supplier Spirit AeroSystems will furlough some 700 workers as a strike by machinists at the plane maker enters its sixth week, a spokesman for the supplier said Friday.

Spirit AeroSystems Holdings Inc. will start furloughing workers later this month in response to the continuing strike at Boeing Co., the aerostructure supplier’s biggest customer. Spirit will implement a 21-day furlough for about 700 workers supporting Boeing’s 777 and 767 jetliner programs beginning Oct.

The latest round of furloughs related to Boeing’s ongoing machinists’s strike isn’t at Boeing (BA). Reuters reports that Spirit Aerosystems (SPR), a fuselage supplier, is the one sending workers home.