Peking University has restricted purchases of food such as mantou, or steamed buns, in student cafeterias to prevent people off campus from buying too much, Beijing News reported on Wednesday.

According to notices hung in the cafeterias, everyone is limited to three mantou, and those who want to buy more need to go to the principal food vendor outside the cafeteria.

The notice was released because the low price of mantou in the university’s cafeterias, which sell for 0.2 yuan (3 US cents) each, had attracted too many off-campus buyers, especially family members of professors and administrators.

The ministries of education and finance have subsidized university cafeterias since 2008 to keep food price low for students, the report said.

However, people off campus often bought dozens of mantou, not leaving enough for the students.