diff --git a/libs/ardour/mute_control.cc b/libs/ardour/mute_control.cc
index 5b38547366..6d5b1e42f0 100644
--- a/libs/ardour/mute_control.cc
+++ b/libs/ardour/mute_control.cc
@@ -188,7 +188,9 @@ MuteControl::automation_run (framepos_t start, pframes_t)
 
 	if (mute >= 0.5 && !muted()) {
 		set_value_unchecked (1.0);  // mute
+		Changed (false, Controllable::NoGroup); /* EMIT SIGNAL */
 	} else if (mute < 0.5 && muted ()) {
 		set_value_unchecked (0.0);  // unmute
+		Changed (false, Controllable::NoGroup); /* EMIT SIGNAL */
 	}
 }