Zimmer Biomet received a warning letter from the FDA about quality violations found at a plant in Warsaw, Indiana. The agency had flagged the issues after a 2016 inspection of the site, but found in a re-inspection earlier this year that the company’s resolution was not up to par.

The FDA inspected Zimmer Biomet’s North Campus manufacturing site in Warsaw in the fall of 2016, serving up a 58-page Form 483 that listed 14 violations. The devicemaker responded in kind with its own lengthy document detailing how it would address the issues. But those efforts appear to have fallen short, as the FDA issued a second Form 483 with 11 observations after its re-inspection in April.

The letter, disclosed Friday in an SEC filing, regarded “observed non-conformities with current good manufacturing practice requirements of the Quality System regulation” at the company’s North Campus facility.

“While the Warning Letter acknowledges our quality remediation plan and actions we’ve already taken to address the FDA’s inspectional observations, it notes violations that require additional action or explanation,” Zimmer Biomet said in the SEC filing.

Zimmer Biomet is working on a response to the letter and plans to send it within 15 business days of receipt. The company expects to meet with the FDA to discuss proposed corrections after it’s sent its response.

That said, the warning letter does not require Zimmer Biomet to pull any products from the market, nor does it restrict the production or shipment of devices from the North Campus plant. It doesn’t affect the company’s ability to seek 510(k) clearance for devices, but premarket approval applications will be on hold until all of the problems have been corrected. While Zimmer Biomet doesn’t currently have any PMA applications before the FDA, future applications could be delayed if the issue drags on.