diff --git a/gtk2_ardour/rc_option_editor.cc b/gtk2_ardour/rc_option_editor.cc
index 1e81186424..cf59952c9d 100644
--- a/gtk2_ardour/rc_option_editor.cc
+++ b/gtk2_ardour/rc_option_editor.cc
@@ -2861,6 +2861,8 @@ RCOptionEditor::RCOptionEditor ()
 		dm->set_sensitive(false);
 	}
 
+	dm->set_note (_("Changes may not be effective until audio-engine restart."));
+
 	add_option (_("Audio"), dm);
 
 	add_option (_("Audio"), new OptionEditorHeading (_("Regions")));