-ADD_ACKNOWLEDGER (Mensural_ligature_engraver, rest);
-ADD_ACKNOWLEDGER (Mensural_ligature_engraver, ligature_head);
+
+void
+Mensural_ligature_engraver::boot ()
+{
+ ADD_LISTENER (Mensural_ligature_engraver, ligature);
+ ADD_ACKNOWLEDGER (Mensural_ligature_engraver, rest);
+ ADD_ACKNOWLEDGER (Mensural_ligature_engraver, ligature_head);
+}