diff --git a/libs/surfaces/osc/osc_select_observer.cc b/libs/surfaces/osc/osc_select_observer.cc
index e5995edf2f..de58cd8916 100644
--- a/libs/surfaces/osc/osc_select_observer.cc
+++ b/libs/surfaces/osc/osc_select_observer.cc
@@ -38,6 +38,7 @@
 #include "ardour/plugin_insert.h"
 #include "ardour/processor.h"
 #include "ardour/readonly_control.h"
+#include "ardour/vca.h"
 
 #include "osc.h"
 #include "osc_select_observer.h"
@@ -195,6 +196,10 @@ OSCSelectObserver::refresh_strip (boost::shared_ptr<ARDOUR::Stripable> new_strip
 	_strip->gain_control()->Changed.connect (strip_connections, MISSING_INVALIDATOR, boost::bind (&OSCSelectObserver::gain_message, this), OSC::instance());
 	gain_automation ();
 
+	boost::shared_ptr<Slavable> slv = boost::dynamic_pointer_cast<Slavable> (_strip);
+	slv->AssignmentChange.connect (strip_connections, MISSING_INVALIDATOR, boost::bind (&OSCSelectObserver::slaved_changed, this, _1, _2), OSC::instance());
+	slaved_changed (boost::shared_ptr<VCA>(), false);
+
 	boost::shared_ptr<Controllable> trim_controllable = boost::dynamic_pointer_cast<Controllable>(_strip->trim_control());
 	if (trim_controllable) {
 		trim_controllable->Changed.connect (strip_connections, MISSING_INVALIDATOR, boost::bind (&OSCSelectObserver::trim_message, this, X_("/select/trimdB"), _strip->trim_control()), OSC::instance());
@@ -1021,3 +1026,28 @@ OSCSelectObserver::eq_restart(int x)
 	//eq_end();
 	eq_init();
 }
+
+void
+OSCSelectObserver::slaved_changed (boost::shared_ptr<VCA> vca, bool state)
+{
+	lo_message reply;
+	reply = lo_message_new ();
+	StripableList stripables;
+	session->get_stripables (stripables);
+	for (StripableList::iterator it = stripables.begin(); it != stripables.end(); ++it) {
+		boost::shared_ptr<Stripable> s = *it;
+
+		// we only want VCAs
+		boost::shared_ptr<VCA> v = boost::dynamic_pointer_cast<VCA> (s);
+		if (v) {
+			lo_message_add_string (reply, v->name().c_str());
+			if (_strip->slaved_to (v)) {
+				lo_message_add_int32 (reply, 1);
+			} else {
+				lo_message_add_int32 (reply, 0);
+			}
+		}
+	}
+	lo_send_message (addr, X_("/select/vcas"), reply);
+	lo_message_free (reply);
+}
diff --git a/libs/surfaces/osc/osc_select_observer.h b/libs/surfaces/osc/osc_select_observer.h
index 0b9f697f2e..063b0e7839 100644
--- a/libs/surfaces/osc/osc_select_observer.h
+++ b/libs/surfaces/osc/osc_select_observer.h
@@ -122,6 +122,7 @@ class OSCSelectObserver
 	void eq_init (void);
 	void eq_end (void);
 	void no_strip ();
+	void slaved_changed (boost::shared_ptr<ARDOUR::VCA> vca, bool state);
 };
 
 #endif /* __osc_oscselectobserver_h__ */