Boeingis shifting engineers from other Everett-based airplane programs to do work on the 787.
"There's some reallocation of resources going on, to meet our weight and time targets," said spokeswoman Yvonne Leach.
Boeing wouldn't comment on the number of engineers involved. Leach said the total is fluctuating.
Last week, Boeing chief executive Jim McNerney told Wall Street analysts that the company was beefing up its 787 engineering corps to ensure that the plane won't come in late or overweight.
Boeing plans to spend an additional $300 million for research and development for the 787 and other programs. That's on top of $2 billion already budgeted.
The plan is for "more engineers and overtime" and is "not at all unanticipated," McNerney said.
"I'd rather be paranoid now than deeply disappointed later."
For its part, Boeing has "aggressive commitments for certification and for entry into service," McNerney said. "We're attacking the weight issues aggressively and the associated schedule issues."
The increased spending for engineering help is not a sign of trouble, he added. "We still see the plane delivered on time, within the performance commitments we've made to our customers."