Christina Aguilera and Demi Lovato are performing together at the Billboard Music Awards

The duo join Janet Jackson, Ariana Grande, Shawn Mendes, Camila Cabello and Dua Lipa, who are all performing at the event.

Get ready to fall in line.

After much speculation, it's been confirmed that Christina Aguilera and Demi Lovato are set to perform their duet Fall In Line together for the first time at this year's Billboard Music Awards. 

The news comes after Christina made her long-awaited comeback last week (4 May) with her first headline release in six years, the 2 Chainz and Ty Dolla $ign assisted Accelerate

The singer also announced her highly anticipated sixth album Liberation, which is due June 15 and features her collaboration with Demi. 

Alongside what's bound to be a powerhouse pop performance, Ariana Grande, Shawn Mendes, Camila Cabello and Dua Lipa are all set to take the stage at the awards, which are being hosted by Kelly Clarkson. 

It's also been announced that Janet Jackson, who has won 10 Billboard Music Awards and been nominated for 18, would be honoured with the Icon Award. Previous recipients of the award include Prince, Cher, Celine Dion and Jennifer Lopez. Janet will also make her first TV performance in nine years at the ceremony. 

The Billboard Music Awards take place on Sunday May 20. 

View Christina's complete Official Chart history, including four Number 1 singles, here.

MORE: Christina Aguilera's Official Top 20 biggest songs