diff --git a/libs/surfaces/osc/osc_route_observer.cc b/libs/surfaces/osc/osc_route_observer.cc
index 9e35a08421..03e2578022 100644
--- a/libs/surfaces/osc/osc_route_observer.cc
+++ b/libs/surfaces/osc/osc_route_observer.cc
@@ -42,8 +42,8 @@ OSCRouteObserver::OSCRouteObserver (boost::shared_ptr<Stripable> s, uint32_t ss,
 	: _strip (s)
 	,ssid (ss)
 	,sur (su)
-	,_last_gain (0.0)
-	,_last_trim (0.0)
+	,_last_gain (-1.0)
+	,_last_trim (-1.0)
 	,_init (true)
 {
 	addr = lo_address_new_from_url 	(sur->remote_url.c_str());
diff --git a/libs/surfaces/osc/osc_select_observer.cc b/libs/surfaces/osc/osc_select_observer.cc
index 9abe578390..1889b04c26 100644
--- a/libs/surfaces/osc/osc_select_observer.cc
+++ b/libs/surfaces/osc/osc_select_observer.cc
@@ -53,8 +53,8 @@ OSCSelectObserver::OSCSelectObserver (boost::shared_ptr<Stripable> s, lo_address
 	: _strip (s)
 	,sur (su)
 	,nsends (0)
-	,_last_gain (0.0)
-	,_last_trim (0.0)
+	,_last_gain (-1.0)
+	,_last_trim (-1.0)
 	,_init (true)
 {
 	addr = lo_address_new_from_url 	(sur->remote_url.c_str());