Publisher HarperCollins is suing Lindsay Lohan for nearly $400,000, claiming the actress never delivered a manuscript for a book deal struck over six years ago, new court papers say.

The “Mean Girls” star and her company Crossheart Productions entered into a contract with HarperCollins on March 27, 2014, for a book that was originally due a year later, the suit filed Thursday in Manhattan Supreme Court alleges.

The publishing house gave Crossheart a $365,000 advance for the deal, which “was given to Lohan,” but the manuscript never materialized — even with a two year extension on the deadline to March 15, 2017, the court papers claim.

LOHAN SNAGS $1M FOR MEMOIR

By September 2018, HarperCollins let the “Freaky Friday” actress’s reps know it was terminating the contract and demanding a return of the advance, the filing says.

Lindsay Lohan attends the MTV Europe Music Awards 2018 held at the Bilbao Exhibition Centre, Spain. (Ian West/PA Images via Getty Images)

“By failing to return the money to the Plaintiff upon the Defendants’ breach of the agreement, the Defendants have received a windfall and have been unjustly enriched,” the suit charges.

LINDSAY LOHAN GIVES PAPARAZZI ADVICE TO MEGHAN MARKLE AND PRINCE HARRY

HarperCollins lawyer Jeffrey Maidenbaum confirmed, “She did not turn in a manuscript and the book was never published.”

Lohan was slated to write a book about her troubled life largely based on a journal she kept during her 2013 stint in rehab. The book deal was slated to be worth $1 million.

LINDSAY LOHAN SAYS NEW ALBUM ‘A REMEMBRANCE OF THINGS’ FROM ‘MY EARLY 20S’

Her reps did not immediately return requests for comment.