diff --git a/libs/ardour/automation_list.cc b/libs/ardour/automation_list.cc
index 9d8bfffc93..0651d018f3 100644
--- a/libs/ardour/automation_list.cc
+++ b/libs/ardour/automation_list.cc
@@ -191,6 +191,9 @@ AutomationList::set_automation_state (AutoState s)
 {
 	if (s != _state) {
 		_state = s;
+		if (s == Write) {
+			_before = &get_state ();
+		}
 		automation_state_changed (s); /* EMIT SIGNAL */
 	}
 }