diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 180bb3dc8d..87bf7972a2 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -1024,7 +1024,6 @@ class Session : public PBD::StatefulDestructible
 	Slave*                  _slave;
 	bool                    _silent;
 	volatile float          _transport_speed;
-	volatile float          _desired_transport_speed;
 	float                   _last_transport_speed;
 	bool                     auto_play_legal;
 	nframes_t               _last_slave_transport_frame;
diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index c863051461..9163dfd5ea 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -1088,7 +1088,6 @@ Session::set_slave_source (SlaveSource src)
 			error << _("No MTC port defined: MTC slaving is impossible.") << endmsg;
 			return;
 		}
-		_desired_transport_speed = _transport_speed;
 		break;
 
 	case MIDIClock:
@@ -1105,12 +1104,10 @@ Session::set_slave_source (SlaveSource src)
 			error << _("No MIDI Clock port defined: MIDI Clock slaving is impossible.") << endmsg;
 			return;
 		}
-		_desired_transport_speed = _transport_speed;
 		break;
 
 	case JACK:
 		_slave = new JACK_Slave (_engine.jack());
-		_desired_transport_speed = _transport_speed;
 		break;
 
 	};