Center graphical markup on staff

[Nuno Trocado]

Hi everyone!
How can I have the wiggly line in the example below centered inside the staff?
Thanks,
Nuno

\score {
  \relative c' {
    c4 d
    s-\markup \override #'(height . 2) \draw-squiggle-line #1 #'(8 . 0) ##f
  }
}