Boeing's 787 order backlog has fallen by eight aircraft, although it is unclear which customer is responsible.
To the end of May the airframer had orders for 835 aircraft from the twinjet family.
But in an update to its books Boeing recorded a loss of eight 787s to 21 June, bringing total cancellations for the type this year to 20.
Etihad Airways cancelled four 787s this year and Fiji's Air Pacific cancelled another eight.
Boeing has not identified the customer behind the additional reduction.
It has recorded orders for 23 new aircraft - including Norwegian's additional 15 737s, six 737s for Air Lease and two 747s - and identified customers for a further 27 previously-ordered jets.
Boeing also listed cancellation of two 777s.