The US Supreme Court ruled Tuesday that Federal Rule of Civil Procedure 23(f), which authorizes an appeal of an order granting or denying class certification within 14 days of the order, is not subject to equitable tolling.

The case, Nutraceutical Corp. v. Lambert, involves a class action suit against Nutraceutical arguing that their marketing of a dietary supplement violated California consumer protection law. Lambert was initially allowed to litigate on behalf of the rest of the class but then, on February 20, 2015, the class was decertified. Lambert then had 14 days to appeal to the Ninth Circuit according to 23(f).

Lambert told the District Court he would appeal and he submitted it on the court’s deadline of March 12. The Motion was denied June 24 and Lambert appealed again 14 days later. When Lambert appealed, Nutraceutical said it was untimely because it had been four months since the decertification.

Lambert argues that because the Rules lack jurisdictional force that the time limits stated therein are malleable, but the court did not agree.

Justice Sonia Sotomayor wrote for the unanimous court that whether it tolls depends on the text of the rule itself. Rule 5(a)(2) states that petitions for permission to appeal “must be filed within the time specified.” Additionally, Rule 26(b) says that a court of appeals “may not extend the time to file … a petition for permission to appeal.”

Sotomayor held that the “Rules express a clear intent to compel rigorous enforcement of Rule 23(f)’s deadline, even where good cause for equitable tolling might otherwise exist.”