French President Emmanuel Macron never seems to be annoyed by people asking for selfies or autographs. But there evidently is one thing that does not sit well with him – people calling him by a nickname.

Macron made his annoyance clear when he was greeted with an all-too-friendly, “How’s it going, Manu,” by a teenager. Macron proceeded to admonish the teenager and a video of the incident was posted on the president’s twitter handle. Macron also told off the teen off for singing the Socialist anthem, the Internationale, in an attempt to criticise Macron’s pro-business reforms.

“No, you can’t do that, no, no, no, no,” Macron told the teenager in French. He then apologised but Macron went on to say: “You’re here, at an official ceremony and you should behave. You can play the fool but today it’s the Marseillaise, the Chant des Partisans [French Resistance song], so you call me Mr President or sir. OK? There you go.”

Macron was visiting Mont Valerien fort, where members of the French Resistance were executed during World War II.