The House of Commons in Canada passed a bill that would make it illegal to hold whales, dolphins and porpoises captive.
The "Free Willy" bill passed on Monday.
Currently, there are only two aquariums in the country housing these animals: Marineland in Niagara Falls and the Vancouver Aquarium.
These aquariums will get to keep the animals they already have, but they will not be allowed to add new ones through capture or breeding.
Violation of the law could cost up to $150,000. The law was first passed by Canada's Senate in 2015.
Now that the House of Commons has approved it, the bill is expected to gain "royal assent," which is the Canadian equivalent of the president signing the legislation into law.