diff --git a/libs/ardour/ardour/port_manager.h b/libs/ardour/ardour/port_manager.h
index e000d8da0a..01d620db30 100644
--- a/libs/ardour/ardour/port_manager.h
+++ b/libs/ardour/ardour/port_manager.h
@@ -146,7 +146,7 @@ public:
 	int disconnect (std::shared_ptr<Port>);
 	int disconnect (std::string const&);
 	int reestablish_ports ();
-	int reconnect_ports ();
+	int reconnect_ports (Session* s = nullptr);
 
 	bool connected (const std::string&);
 	bool physically_connected (const std::string&);
diff --git a/libs/ardour/port_manager.cc b/libs/ardour/port_manager.cc
index 697476d90f..e5a160327e 100644
--- a/libs/ardour/port_manager.cc
+++ b/libs/ardour/port_manager.cc
@@ -920,7 +920,7 @@ PortManager::set_pretty_names (std::vector<std::string> const& port_names, DataT
 }
 
 int
-PortManager::reconnect_ports ()
+PortManager::reconnect_ports (Session* s)
 {
 	std::shared_ptr<Ports const> p = _ports.reader ();
 
@@ -928,7 +928,10 @@ PortManager::reconnect_ports ()
 
 	DEBUG_TRACE (DEBUG::Ports, string_compose ("reconnect %1 ports\n", p->size ()));
 
-	Session* s = AudioEngine::instance ()->session ();
+	if (!s) {
+		s = AudioEngine::instance ()->session ();
+	}
+
 	if (s && s->master_out() && !s->master_out ()->output()->has_ext_connection()) {
 		s->auto_connect_master_bus ();
 	}
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 7646a13321..d95d7f8c26 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -1670,7 +1670,7 @@ Session::hookup_io ()
 
 	/* Get everything connected */
 
-	AudioEngine::instance()->reconnect_ports ();
+	AudioEngine::instance()->reconnect_ports (this);
 
 	AfterConnect (); /* EMIT SIGNAL */