The United States Court of Appeals for the Seventh Circuit ruled on Tuesday that two insurance companies must cover the costs incurred by a window company that successfully defended itself in a class-action lawsuit.

Kolbe & Kolbe Millwork was sued by a group of homeowners in February 2014 who claimed that the company’s windows, which were covered under a ten-year warranty, leaked water. Kolbe hired United States Fire Insurance Company and Fireman’s Fund Insurance Company to fight the defective-product claims.

The class-action lawsuit’s claims against Kolbe were eventually dismissed, but U.S. Fire Insurance and Fireman’s Fund Insurance sought declarations that they did not have to pay for Kolbe’s defense costs. According to court documents, the insurers claimed that Kolbe’s insurance policies “did not cover the ‘direct’ cost of replacing any faulty windows, because the policies did not cover damage to Kolbe’s own product where, as here, the source of the damage was a problem with that product itself.” They also claimed that “the policies likewise did not apply to any indirect or ‘consequential’ injuries to the plaintiffs’ homes … because each home formed an ‘integrated system’ with Kolbe’s windows—and thus the entire house should be treated as Kolbe’s ‘product’ for insurance‐coverage purposes.”

The district court accepted the first argument but rejected the second, and initially awarded only a partial judgment to the insurance companies.

United States Fire later filed a motion for summary judgment, arguing that a recent Wisconsin Supreme Court decision involving a dietary supplement “absolved the insurers of their duty to defend Kolbe in the underlying suit,” court documents read. The district court granted the motion, and Kolbe appealed that ruling to the Seventh Circuit.

The lawsuit involving the diet supplement claimed that a faulty ingredient in the pills didn’t damage the effectiveness of the pill because it was part of the supplement as a whole. Reflecting that decision, the lower court ruled that Kolbe’s windows were part of a system that included an entire house. Because of that, any water damage to the houses was the same as damage to Kolbe’s products.

In Tuesday’s opinion, the Seventh Circuit court said the district court made a mistake in applying that earlier Wisconsin Supreme Court ruling to Kolbe’s case. In the lawsuit involving the dietary supplement, the plaintiff sought damages because they couldn’t use the final product as a whole because of the inclusion of an incorrect ingredient. In Kolbe’s case, “the homeowners sought compensation for the repair or replacement of individual elements of a larger structure. This kind of particularized demand was not at issue in (the dietary supplement case),” according to court documents.

“The parties agree that Kolbe’s windows, which Kolbe manufactured, are Kolbe’s ‘goods or products’ under the first part of the definition—so Kolbe’s insurers are not on the hook for the cost of replacing any windows that are defective (or, relatedly, for any losses stemming from replacement operations),” the appeals court ruling reads. “The parties disagree, however, as to whether the walls and other elements of the plaintiffs’ homes constitute Kolbe’s ‘product’ under the second part of the definition, such that coverage for any damage to those materials is likewise extinguished by the exclusion. Kolbe says not, because Kolbe did not ‘furnish’ any of the drywall, wood framing, stucco, or bricks at issue.”