Shanghai officials are calling for residents to drop their longstanding habit of hanging around the city streets in pyjamas.

The initiative is meant to bring people’s culture closer to international standards, local media reported on Friday.

In China wearing pyjamas was considered a sign of prosperity several decades ago, as it meant people could afford not to sleep in their day-time clothes. The habit became rooted in society ever since, and now many Shanghainese consider it appropriate to wear nightwear outside their bedrooms.

“Pyjamas are also a type of clothes. They’re comfortable, and it's no big deal since everyone wears them outside,” a resident said.

The anti-pyjamas campaign is not the first of its kind. In the 1990s, Shanghai officials tried to fight the custom, but with little success.

Pyjama strolls are not the only controversial tradition that some Chinese officials want to eradicate. After being awarded the 2008 Olympics, the country launched a campaign against the ancient tradition of public spitting. Such behaviour is considered rude by westerners, but the Chinese believe powerful expectoration is good for the health.