Litterbugs are no longer welcome on the roof of the world.
As Nepal welcomes trekkers at the start of the climbing season on Everest, it is introducing new rules in the hope of taking more control over the world's tallest mountain.
The rules, which include a demand that climbers bring down their own trash, are aimed at making the mountain safer and cleaner, officials said.
If the hundreds of Western climbers each year clean up after themselves, "we can be assured no new garbage will be added", said Kapindra Rai, of the Everest pollution control committee.
But what of the trash that is already up there? Tons of crumpled food wrappers, shredded tents, abandoned ropes and spent oxygen cylinders now litter climbing routes, earning Everest the shame of being called "the world's highest garbage dump".
More than 4,000 climbers have scaled the 8,850-metre summit since 1953, when it was first conquered by New Zealand climber Edmund Hillary and his Sherpa guide Tenzing Norgay.
Yet Nepalese authorities have never had much control over what happens at the mountain's extreme altitudes.
Instead, private trekking companies are left to organise logistics and report any problems.
They are also left to clear the trash, launching yearly springtime expeditions to bring down whatever hasn't been covered over by ice and snow. "There is no way to say how much garbage is still left on Everest," said Dawa Steven Sherpa, who has led Eco Everest Expeditions since 2008. "It is impossible to say what is under the ice."
Sherpas and environmentalists applauded the new clean-up rules. "They should have been introduced a long time back," said Ang Tshering, president of the Nepal Mountaineering Association. "It is going to make sure climbers obey the rules."
For the government, the mountain is the centrepiece of Nepal's tourism industry, which earns the country US$3.3 million each year in climbing fees alone.
The industry also supports tens of thousands of Nepalese hotel owners, trekking guides and porters.
While the government has long asked climbers to clear their trash, there was little or no enforcement despite threats to withhold climbing deposits for polluting teams.
To enforce its new rubbish-clearing rule, the government is setting up its first Everest base camp tent for officials to check that each climber descends with approximately 8kg of trash - the amount the government estimates an exhausted climber discards along the route.
If the base camp is successful, the model will be rolled out to other climbing routes.
"We are not asking climbers to search for and pick up trash left by someone else. We just want them to bring back what they took up," the Maddhu Sudan Burlakoti, head of mountaineering at the Tourism Ministry.
The new measures are part of a wider effort by Nepal's government to increase revenues from its trekking industry.
Last month, the government said it would slash Everest climbing fees to US$11,000 a person next year to attract more mountaineers, who currently pay US$25,000 unless they are part of a group receiving a discount.
Groups of seven pay only US$70,000. Fees for other mountains will also be reduced.