On 25 August Serebro announced a new single called "Serdtse patsanki" (Tomboy's Heart), which is a soundtrack for the movie "PATSANKI", and on 5 September 2016, Serebro premiered the full version of the song. Favorskaya announced she'd be leaving the group in August 2017, and an open casting was announced to find her replacement. The three finalists from the open casting were later revealed to be Anastasia Gribkhova, Tatiana Morgunova, and Anastasia Popova. Following several stages of auditions, Morgunova was announced as Favorskaya's replacement in November 2017. They performed live shows as a quartet until the end of 2017.