When Hilary Duff told her 6-year-old son Luca that he was going to be a big brother, he wasn’t immediately thrilled. In fact, Duff says, he’s “a little nervous” about the prospect of having a little sister.

The Huffington Post says Duff announced in June that she’s expecting her second child with boyfriend Matthew Koma. It's the couple's first child together, a daughter. Duff says Luca has come around to the idea of another person in the fold.