It’s official: Hong Kong—a major market for elephant ivory—will end sales of the “white gold” by the end of 2021.

Lawmakers gave the go-ahead on January 31 to a four-year plan that would phase out the city-state’s legal retail market, which conservationists and advocates say helps fuel the slaughter of more than 30,000 African elephants annually by serving as a cover for ivory traded on the black market. Approval of the measure, which the Associated Press reported passed by a vote of 49-4, comes more than two years after Hong Kong’s Chief Executive Leung Chun-ying promised to shut down the ivory trade, and more than a year after the government submitted a plan for ending sales.

In addition to shutting down the ivory market, the plan also includes harsher penalties for smugglers: Under the new law the maximum prison sentence will increase from two years to 10, and the fine will double to $1.3 million.

Conservationists applauded the news but expressed reservations about the long timetable for closing ivory shops.

“Every positive step to us concerning elephants is good news,” says Philip Muruthi, vice president of species protection for the Nairobi-based African Wildlife Foundation. “But the urgency of the issue as it pertains to elephants hasn’t been taken seriously here.”

Indeed, elephants are being killed at unsustainable rates for their tusks, which are carved into everything from artwork to chopsticks and sold—illegally—across borders, although countries are free to allow domestic sales. Only an estimated 350,000 African elephants remain, a drop from about 490,000 a decade ago—with poaching the main culprit for the ongoing decline.

Mainland China, which shut down its legal ivory trade last year, is the world’s largest consumer of ivory. Because of Hong Kong’s close proximity to China, and the existence of its own booming legal market, it too has emerged as a key driver of the poaching crisis.

As Laurel Neme reported for Wildlife Watch in June 2016:

Tens of thousands of ivory items are displayed for sale in high-rent tourist areas [in Hong Kong] while seizures of huge quantities of ivory by customs authorities confirm its place as an ivory smuggling hub.

After the international trade in ivory was banned in 1989, the city-state instituted a license system for existing legally acquired commercial ivory stocks held by private traders, which at the time totaled 665 metric tons. Studies suggest that amount should’ve been exhausted by 2004, but today roughly 370 licensed ivory traders collectively hold about 77 tons of ivory.”

Undercover investigations cited by Neme revealed that Hong Kong’s traders routinely replenish their legally held private ivory stocks with ivory from the black market, made easier in part because of a requirement that licenses record only the weight of ivory and not specific products.

Ivory shop owners and licensed traders won’t be compensated under the shutdown plan, even though the Associated Press reported that they demanded tens of millions of dollars in return for giving up their ivory stockpiles. The three-year grace period, as well as the fact that traders generally rely on ivory for only a small portion of their business, were given as reasons for refusing to pay them.

A three-year period for closing the ivory market means that enforcement is important, says Richard Thomas, spokesman for TRAFFIC, the wildlife trade monitoring organization. "With the later implementation of the Hong Kong ban, those with ivory in mainland China might perceive a potential back door for unloading their stock,” he says. “It will be critical to closely monitor and document ivory stockpiles and secure borders to ensure this door remains firmly shut."

Muruthi adds that he hopes Hong Kong’s decision will spur other countries—namely Thailand, Vietnam, and Laos—to shut down their legal markets, especially because laundering of illegal ivory is a widespread problem and the closure of China’s shops may prompt ivory-seekers to look elsewhere.