\repeat volta 2 {} doesn't repeat notes in the .MIDI file

[Disc Magnet]

I have the following LilyPond file:


\score {
    \new PianoStaff <<
        \set PianoStaff.midiInstrument = "acoustic grand"

        \new Staff {
            \tempo 4 = 120
            \relative c' {
                c e g e
                \repeat volta 2 {
                    c f a f
                }
            }
        }
    >>
    \midi { }
    \layout{ }
}

However, in the midi generated only 8 notes are played: C E G E C F A F.

I expect a total of 12 notes to be played: C E G E C F A F C F A F.

How can I make the repeat effective in the MIDI file as well?