diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 1920704c24..22892b574b 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -195,7 +195,7 @@ Session::Session (AudioEngine &eng,
 	, _default_transport_speed (1.0)
 	, _default_engine_speed (1.0)
 	, _last_transport_speed (1.0)
-	, _requested_transport_speed (0.0)
+	, _requested_transport_speed (std::numeric_limits<double>::max())
 	, _signalled_varispeed (0)
 	, auto_play_legal (false)
 	, _requested_return_sample (-1)
diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index a9cf463db4..b75e0cd96c 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -586,10 +586,10 @@ Session::start_transport ()
 	maybe_allow_only_loop ();
 	maybe_allow_only_punch ();
 
-	if (_requested_transport_speed) {
+	if (_requested_transport_speed != std::numeric_limits<double>::max()) {
 		_engine_speed = fabs (_requested_transport_speed);
 		_transport_speed = _requested_transport_speed > 0 ? 1 : -1;
-		_requested_transport_speed = 0;
+		_requested_transport_speed = std::numeric_limits<double>::max();;
 	} else {
 		_transport_speed = _default_transport_speed;
 		_engine_speed = _default_engine_speed;