Matthew McConaughey Rapped for 13 Hours Straight After Accidentally Smoking Snoop Dogg's Weed

Matthew McConaughey and Snoop Dogg both star in The Beach Bum, in theaters now

Snoop Dogg did his best to make sure Matthew McConaughey‘s weed smoking in The Beach Bum was as authentic as possible — even if that meant the actor spent half a day uttering nonsense.

While filming the comedy (out now), the “Gin and Juice” rapper switched out one of the film’s prop joints for some real marijuana, accidentally getting McConaughey stoned out of his mind.

McConaughey, who payed the titular beach bum named Moondog in the process, was pretty surprised by the switch. He thought he was smoking joints stuffed with oregano.

The actor, 49, walked Jimmy Kimmel through what happened during an appearance alongside Snoop Dogg, 47, on Thursday’s episode of the ABC late night show. Turns out this all went down during the first take of the first scene McConaughey and Snoop were filming together for the movie.

“We do the scene and it’s about an eight-minute take, [which is] a long take if you’re passing a joint back and forth and you’re smoking hardcore to the heels of your feet,” McConaughey explained on Jimmy Kimmel Live. “So the scene goes on and right after the scene I just feel like, ‘Man, I’m not sure that was a prop…’ And I look over and Snoop goes, ‘Yo, Moondog, that wasn’t prop weed, that was Snoop weed.’ ”

“I said, ‘Okay man. Buckle up because here we go!’ ” McConaughey said.

Chelsea Lauren/Variety/REX/Shutterstock

From there, things got messy. According to Snoop, McConaughey rapped for “13 hours straight.”

“I didn’t speak another word of English, really,” McConaughey said. “It was one of those highs where I didn’t really catch my breath until 5:30 the next day.”

Snoop had a good sense of humor about it, filling McConaughey in on the details. The actor recalls Snoop telling him, “You were great, Moondog. You hit 4 in the park home runs.”

The Beach Bum is acclaimed director Harmony Korine’s first film since 2012’s Spring Breakers, and brings McConaughey back to his roots with comedies like Dazed and Confused.

In addition to McConaughey and Snoop, the film also stars Isla Fisher, Stefania LaVie Owen, Zac Efron, Martin Lawrence, Jonah Hill and Jimmy Buffett.

As for McConaughey and Snoop’s friendship, the rapper said on Thursday’s Jimmy Kimmel Live that the two were destined to be pals.

“It’s magic. I think certain people in life are meant for each other,” he said. “I think Matthew and I were meant for each other. It’s meant to be.”

The Beach Bum is in theaters now.