Pope Francis is warning his new cardinals to keep the partying to a minimum — and keep their egos in check — when they are formally elevated at a Vatican ceremony next month.

In a letter written to the 20 new princes of the church published Friday in the Vatican newspaper L'Osservatore Romano, Francis warned the cardinals to avoid the type of ostentatious festivities that "stun worse than grappa on an empty stomach."

Traditionally, new cardinals are feted with lavish parties, often funded by well-meaning parishioners, following the ceremony where they receive their red hats.

Some of the new cardinals hail from places that have never before had a "prince of the church," including Cape Verde, Myanmar and Tonga. Others come from the developing world, including Panama, Mozambique and Thailand.