--- src/Dialogs.vala
+++ src/Dialogs.vala
@@ -31,7 +31,7 @@
 
 public bool confirm_warn_developer_changed(int number) {
     Gtk.MessageDialog dialog = new Gtk.MessageDialog.with_markup(AppWindow.get_instance(),
-        Gtk.DialogFlags.MODAL, Gtk.MessageType.WARNING, Gtk.ButtonsType.NONE,
+        Gtk.DialogFlags.MODAL, Gtk.MessageType.WARNING, Gtk.ButtonsType.NONE, "%s",
         "<span weight=\"bold\" size=\"larger\">%s</span>".printf(ngettext("Switching developers will undo all changes you have made to this photo in Shotwell",
         "Switching developers will undo all changes you have made to these photos in Shotwell", number)));