One of the film's best known comical scenes originated from an acting gaffe. While signing a written affidavit, prostitute Manka "Obligatsiya" asks Zheglov whether her nickname (Russian for government bond) is properly spelled with an "O" or an "A". Zheglov responds absentmindedly with the correct spelling, before realizing what she was asking and directing her to sign her real name instead. Actress Larisa Udovichenko has revealed that the entire moment was unscripted and she actually asked about the spelling because she had been unsure, with Vysotsky deciding to play along. Director Stanislav Govorukhin liked the impromptu and included it in the film.