'Titanic's' Kate Winslet says Matthew McConaughey almost played Jack

Leonardo DiCaprio won over fans’ hearts in “Titanic” 20 years ago, but the actor almost wasn't cast as Jack Dawson.

Kate Winslet, who played Rose DeWitt Bukator, appeared on “The Late Show with Stephen Colbert” and dropped details on when she auditioned for James Cameron’s 1997 film. The 42-year-old actress said Matthew McConaughey was initially the favorite to play Jack.

"I auditioned with Matthew, isn't that weird?" Winslet told Colbert on Friday. "Never said that in public before. I auditioned with Matthew, which was completely fantastic…It just wouldn't have been the whole, Jack and Rose, Kate and Leo thing."

Cameron’s insistence for DiCaprio to take on the role ultimately prevailed despite Paramount Pictures' preference toward McConaughey.

Winslet also revealed Cameron, not DiCaprio, drew the infamous sketch in the movie.

Actor Matthew McConaughey arrives at the Hollywood Film Awards in Beverly Hills, California, U.S., November 6, 2016.  REUTERS/Mario Anzuoni - HT1ECB705L16C

Matthew McConaughey was almost cast as Jack in "Titanic," Kate Winslet said.  (Reuters)

As for promising to never let Jack go, the 42-year-old actress joked she “totally lied” to DiCaprio and said “he just should have tried harder to get on that door.”

"Because I think we would have (fit)!" Winslet said before she and Colbert recreated the scene on the talk show host’s desk.

Kate Winslet, nominated for Best Supporting Actress for her role in "Steve Jobs," and Leonardo DiCaprio, nominated for Best Actor for his role in "The Revenant," arrive at the 88th Academy Awards in Hollywood, California February 28, 2016.    REUTERS/Lucy Nicholson - TB3EC2T02SUXU

Kate Winslet and Leonardo DiCaprio have maintained a close friendship since filming 'Titanic" 20 years ago.  (Reuters)

Cameron also addressed the hotly debated scene with Vanity Fair last month, saying Jack “had to die” for his character to serve a purpose.

“Obviously it was an artistic choice, the thing was just big enough to hold her, and not big enough to hold him,” the director said. “The film is about death and separation; he had to die. So whether it was that, or whether a smoke stack fell on him, he was going down.”

Katherine Lam is a breaking and trending news digital producer for Fox News. Follow her on Twitter at @bykatherinelam