Madonna covered Britney Spears' song 'Toxic' to mark the pop star's birthday, as well as World AIDS day.
The 59-year-old hitmaker paid tribute to her pal with a rendition of her famous track before wishing the singer a happy birthday on social media.
Captioning the video, Madonna wrote: "Silence =Death! ... Song For World AIDS Day! ... #toxic #poisonparadise @britneyspears. Happy Birthday!! (sic)"
Madonna and Britney teamed up for the track 'Me Against the Music' for Britney's 2003 album 'In the Zone'. That year, the pair also famously kissed on stage at the MTV Video Music Awards when Britney and Christina were duetting on Madonna's track 'Like a Virgin'.