Later in 747, Li Linfu tried to use yet another case to undermine Li Heng. The general Wang Zhongsi, who was raised with Li Heng inside the palace on account of the fact that his father Wang Haibin () had died in battle in service to the empire, was accused of interfering with the campaign of another general, Dong Yan'guang (), against Tibetan Empire. Li Linfu broadened the accusation to an accusation that Wang was planning to start a coup to overthrow Emperor Xuanzong and replace him with Li Heng. At the intercession of another general, Geshu Han, however, Wang was spared from death, and Li Heng was not implicated. It was said that during this time period, Li Linfu made other attempts to undermine Li Heng, but with Gao Lishi and Zhang Shuo's son Zhang Ji (), who had married Li Heng's sister Princess Ningqing, protecting Li Heng, Li Heng escaped unharmed each time.