A Beijing court has sided with drug giant Pfizer Inc. in a ruling against local drug makers keen to sell generic versions of Viagra in China — though it was unclear if the decision would dent the widespread availability of fake versions of the impotence drug.

The Beijing No. 1 Intermediate People’s Court on Monday overturned a 2004 decision by China’s patent review board. An official, who like most Chinese bureaucrats refused to give her name, confirmed the decision but said she could not provide other information.