The Writers Guild of America West has reached a $5.25 million settlement with Disney for interest owed on late paid residuals for five Fox animated series: “The Simpsons,” “Family Guy,” “American Dad,” “The Cleveland Show” and “Futurama.”

The guild, in a message sent Friday to members as part of its WGAW Connect magazine, said it was the largest interest-only settlement in its history. The WGA West said that more than 250 affected writers have already received checks for their portions of the interest collected.

The WGA said a 2017 audit revealed that Fox had failed to make certain residuals payments on these series. After it contacted Fox, the studio found that an internal error had led to a widespread failure to pay the residuals for reuse in the foreign free television markets over several years, resulting in Fox paying millions of dollars in late paid residuals to the Guild in 2018, which was then distributed to the credited writers.

Disney acquired most of the Fox entertainment assets in 2019. The WGA West said it made a claim for the interest owed on late payments and set the arbitration for March 2020. The guild said that despite some resistance from Disney, including an attempt to delay the hearing, the company ultimately agreed to pay the entire amount due and the writers received the $5.25 million in interest.

“The Guild aggressively pursues interest when writers are not paid on time,” the WGA told its members. “If you are not paid within seven days of commencement of writing, delivery of a step, your weekly services, or when your residuals are due, interest on the late payment accrues at a rate up to 18% per year.”

The WGA gained a major foothold in animation writing with coverage of “The Simpsons” in its early years, leading to coverage on other Fox animated series. The guild shares jurisdiction on animation writing with the International Alliance of Theatrical Stage Employees, which covers feature animated work at terms that aren’t as sweet as the WGA’s.

Disney did not immediately return Variety’s request for comment.