Matthew McConaughey and his girlfriend Camila Alves -- whose son Levi turns 1 next month - have announced they're expecting their second child.

"Happy Father's Day. It's my first, and the last 11 months with Levi and Camila have been the most rewarding adventure to date," McConaughey, 39, wrote on his website Sunday.

"We have more blessed news to celebrate this Father's Day that [will] make this time next year double the fun. Levi is going to be a big brother... Yeah, we pulled off the greatest miracle in the world one more time, Camila and I are expecting our second child, bringing more life into the world, making more to live for. The future looks bright as the family grows.... just keep livin, Matthew and Camila."

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McConaughey has been with Alves, a Brazilian model, for more than two years. When she welcomed their son Levi last July, Alves said she had a 60-hour labor, and "Matthew was there the entire time."

"We went 14 hours with no epidural, having contractions every two minutes," she told Extra. "It was the best dance we ever had."

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Of their son, she said, "He's straight up his father. He has my lips, but he looks so much like Matthew. He's a white boy."

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Their son, McConaughey recently told Rachael Ray, "is doing well, man. Five stamps on the passport ... He's an easy traveler."

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