Watch John Oliver dress up as Sia with Stephen Colbert for the Democratic Party’s ‘Our Fight Song’

The comedic pair helped "upgrade" the song that's been written in support of Hillary Clinton's bid for The White House

John Oliver has dressed up as Sia to help Stephen Colbert “upgrade” the Democrat Party’s ‘Our Fight Song’ for a sketch on the latter’s The Late Show.

‘Our Fight Song’ has emerged during the Democratic National Convention in Philadelphia, PA this week and features a host of well-known names, including Elizabeth Banks, Aisha Tyler and Frozen‘s Idina Menzel, contributing vocal parts to the totally a cappella song.

As part of Colbert’s cold open for last night’s edition of his talk show, the host enlisted the help of Last Week Tonight‘s John Oliver to “upgrade” the video by adding their own vocal and video additions to the clip. Towards the end of the video, Oliver is shown in the now-trademark wig and bow worn by Sia, warning that “this song is going to irritate people.”

Watch the clip below.

Colbert has been broadcasting his show live for the past two weeks to provide a running commentary on both the DNC and last week’s Republican party equivalent, where the party nominated Donald Trump as its candidate for the White House.

During one of last week’s Republican-themed shows, Colbert reunited with The Daily Show‘s John Stewart for a sketch that attempted to “make sense of Trump’s candidacy”. Watch it in full here.