Marijuana use for any reason is still technically illegal in the eyes of the federal government.
And White House press secretary Sean Spicer hinted the Trump administration might start reminding states of that fact soon.
Spicer said: "There's two distinct issues here: medical marijuana and recreational marijuana. ... There is still a federal law that we need to abide by when it comes to recreational marijuana and other drugs of that nature."
States that have legalized medical marijuana use are safe from federal interference, thanks to a 2014 budget rule passed by Congress.
But the eight states and the District of Columbia that have legalized recreational pot use don't have any such protection from federal drug enforcement.
The Obama administration generally respected the state laws when it came to drug enforcement. President Trump's Department of Justice might not be as forgiving.
Spicer said: "That's a question for the Department of Justice. I do believe that you'll see greater enforcement of it."