Boeing said on Monday that repairs are needed in the tail sections of some of its new 787s, although it said there's no immediate safety concern.

Boeing has delivered five of the planes since September to Japan's All Nippon Airways. It has built dozens more, including many that need to be reworked to fix various manufacturing issues.

A Boeing Co. spokeswoman said on Monday that inspections were under way to determine which planes need the latest repairs, including the planes that have gone to ANA.

It said the tail issue involves shims, which are spacers between the 787's skin and the parts that support it. Most airliners are built using aluminum skin. The 787 is the first major airliner with a skin made almost entirely from carbon fiber, which is essentially a high-tech plastic and intended to be lighter and stronger than aluminum.

Airlines have generally planned to use the mid-sized 787 on long-haul flights, especially on international routes that have consistent demand but not enough to fill a larger plane.

The issue was first reported over the weekend by aerospace news website Flightglobal.com.

Boeing stock fell 88 cents to close at $75.46.