Supernatural's Jensen Ackles may be used to fighting off demons as Dean Winchester but now he is trying out the new role of first time dad.

Danneel Harris Ackles, Jensen's wife and new mother of Justice Jay "JJ" Ackles, announced the birth of their daughter late on Thursday night.

"We are happy to announce the birth of our precious baby girl, Justice Jay "JJ" Ackles. She was born happy and healthy on May 30th," tweeted  the One Tree Hill actress.

A fan later tweeted, "Justice Ackles sounds like she's gonna be a superhero," to which the proud mom replied, "that is what I intended."

The couple first disclosed their pregnancy in January, according to People. Shortly afterward, the 34-year-old Danneel debuted her baby bump at the People's Choice Awards where Supernatural took home the award for Favorite Sci-fi/Fantasy Show.

Jensen and Dannell met on the set of Ten Inch Hero back in 2007 and married in 2010. Costar Jared Padalecki also married his wife Genevieve Cortese during the same year and the couple welcomed their first child, Thomas Colton Padalecki, in March of 2012.

Jensen will have plenty of time to spend with his new daughter before filming resumes this summer for Supernatural season 9.