Dan Reynolds' daughter was ''upset'' when she learned she was going to have a baby brother.

The Imagine Dragons frontman is set to become a father to his first son when his wife Aja Volkman gives birth later this year, and has said that his eldest daughter Arrow, six, was horrified at the news, because she said she ''really doesn't want to have a brother'' if he's anything like a boy she knows.

Dan said: ''Arrow was pretty upset. I told her she was having a brother and you know what she said to me? I can't tell you all of this story because it puts someone on blast but she said, 'I really don't want to have a brother if it's like ... and then she said a boy that she knows, but if it's like River - which is [my bandmate Daniel Wayne Sermon's] son - then I'm okay with it.'

''She was almost in tears about it. I said, 'Our son will be like River, I promise.' I really hope that's true!''

The 31-year-old singer also has twin daughters Gia and Coco, two, with Aja, and has said he's ''a little nervous'' about having a son, so he's been getting all the tips he can from bandmate Wayne, who has two boys of his own.

He added to People magazine: ''I'm a little nervous. I don't know what to expect, but Wayne has some boys so I've sat down and got some parenthood advice. He's a great father. My wife has to bear the brunt of it right now so she's a badass.''

The 'Thunder' hitmaker announced he was set to become a father again last month.

He said: ''I've been on the road for a decade now. I'm looking to take a little bit of time off. I have three little girls, and well, I have one on the way. I actually haven't told anybody that. There it is. The news is out. We just found out we're having a boy [in] October.''