Dutch lawmakers have made a “historic breakthrough” on marijuana legalization, passing a measure in the lower house of Parliament to decriminalize cannabis cultivation.

MPs narrowly passed a bill Tuesday that would build on the country’s existing policies of relaxed enforcement of marijuana consumption and sale. However, the legislation still needs to clear the upper house, where it isn’t certain to win the majority’s support, according to The Associated Press.

Nonetheless, Alexander Pechtold, leader of the Democrats 66 party, called the bill’s passage a “historic breakthrough.”

Vera Bergkamp, a member of the D66 party, introduced the bill. She said in a statement that regulating the marijuana industry reflects the desires of local officials and the public.

“This puts an end to the lopsided tolerance policy where you can sell weed, but cannot grow,” Bergkamp said.

The Netherlands has long had a tolerance policy on soft drugs. Selling pot in coffee shops is against the law but is not prosecuted, and individuals are allowed to possess small quantities of pot. But the rules are stricter for growing marijuana, and possessing more than five plants can lead to prosecution.

Police in the Netherlands have cracked down on pot cultivation. In 2015, they busted nearly 6,000 marijuana grow operations, according to the Dutch news site NRC.

According to the Financial Times, the measure that advanced Tuesday would eliminate a “legal grey area” by regulating the supply chain and ending a loophole that currently makes it possible to prosecute sellers for transporting marijuana to their shops.

In a Facebook post, Pechtold argued that regulating the industry would be good for public health, saying it would free up police to focus on more serious crimes and would benefit the public through tax revenue.