CHICAGO (AP) -- Boeing says repairs are needed in the tail sections of some of its new 787s. It says there is no immediate safety concern and the planes will keep flying.

Boeing has delivered five of the planes since September. All of them went to Japan's All Nippon Airways. Boeing has had to rework dozens of 787s that rolled off its assembly line. It said on Monday that the most recent issue involves shims, which act as spacers between the 787's skin and the parts that support it.

A spokeswoman says Boeing is still inspecting planes to see how many will need the repair. The issue was first reported over the weekend by aerospace news website Flightglobal.com.

Boeing stock fell 91 cents to $75.43 in afternoon trading.