A South Korean appellate court on Tuesday upheld the jail sentence of Shin Jeong-ah, the former Korean art-history professor who faked a Yale doctorate degree.

“Shin’s allegation that she earned a doctorate degree in the United States proved false,” wrote the court, according to The Korea Times. Shin, 36, will now serve 18 months in prison.

The ruling comes one year after Shin was fired from Dongguk University after her supposed doctorate was revealed to be fake, a secret she had managed to keep as she used the degree to fuel her ascension to the apex of the Korean art world.

She did it in part with the help of an administrative error by Yale, which now faces a $50 million lawsuit from Dongguk alleging negligence. In 2005, Shin forged a letter from an official in the Yale Graduate School that documented her degree; when Dongguk officials contacted Yale to authenticate that letter, Yale administrators errantly vouched for it.

Then, when “Shingate” broke last summer, Yale officials asserted they had never verified that Shin had graduated from the University. But a few months later, they realized they had indeed confirmed Shin had received a Yale doctorate — though only because of what they called an administrative error — and apologized to Dongguk.

That was not enough for the Korean university, which in March sued Yale in federal court. The University has since asked for the lawsuit to be dismissed.

Shin, meanwhile, has seven days to file another appeal, said Kim Myung-su, a spokesperson for the Seoul Western District Court. The court on Tuesday also upheld the conviction of Shin’s lover, former presidential aide Byeon Yang-kyoon GRD ’87, on charges of influence peddling.

—The Associated Press contributed reporting from Seoul.