diff --git a/gtk2_ardour/mixer_strip.cc b/gtk2_ardour/mixer_strip.cc
index 9eed9ffebc..e2c80da98e 100644
--- a/gtk2_ardour/mixer_strip.cc
+++ b/gtk2_ardour/mixer_strip.cc
@@ -365,6 +365,14 @@ MixerStrip::init ()
 		global_vpacker.pack_start (output_button, Gtk::PACK_SHRINK);
 	}
 
+	midi_input_enable_button.set_size_request (PX_SCALE(19), PX_SCALE(19));
+	midi_input_enable_button.set_name ("midi input button");
+	midi_input_enable_button.set_elements ((ArdourButton::Element)(ArdourButton::Edge|ArdourButton::Body|ArdourButton::VectorIcon));
+	midi_input_enable_button.set_icon (ArdourIcon::DinMidi);
+	midi_input_enable_button.signal_button_press_event().connect (sigc::mem_fun (*this, &MixerStrip::input_active_button_press), false);
+	midi_input_enable_button.signal_button_release_event().connect (sigc::mem_fun (*this, &MixerStrip::input_active_button_release), false);
+	set_tooltip (midi_input_enable_button, _("Enable/Disable MIDI input"));
+
 #ifndef MIXBUS
 	//add a spacer underneath the master bus;
 	//this fills the area that is taken up by the scrollbar on the tracks;
@@ -715,15 +723,9 @@ MixerStrip::set_route (std::shared_ptr<Route> rt)
 	update_trim_control();
 
 	if (is_midi_track()) {
-
-		midi_input_enable_button.set_size_request (PX_SCALE(19), PX_SCALE(19));
-		midi_input_enable_button.set_name ("midi input button");
-		midi_input_enable_button.set_elements ((ArdourButton::Element)(ArdourButton::Edge|ArdourButton::Body|ArdourButton::VectorIcon));
-		midi_input_enable_button.set_icon (ArdourIcon::DinMidi);
-		midi_input_enable_button.signal_button_press_event().connect (sigc::mem_fun (*this, &MixerStrip::input_active_button_press), false);
-		midi_input_enable_button.signal_button_release_event().connect (sigc::mem_fun (*this, &MixerStrip::input_active_button_release), false);
-		set_tooltip (midi_input_enable_button, _("Enable/Disable MIDI input"));
-		input_button_box.pack_start (midi_input_enable_button, false, false);
+		if (!midi_input_enable_button.get_parent()) {
+			input_button_box.pack_start (midi_input_enable_button, false, false);
+		}
 
 		/* get current state */
 		midi_input_status_changed ();
diff --git a/libs/ardour/ardour/port_manager.h b/libs/ardour/ardour/port_manager.h
index ed9605e808..5009e7492c 100644
--- a/libs/ardour/ardour/port_manager.h
+++ b/libs/ardour/ardour/port_manager.h
@@ -151,7 +151,7 @@ public:
 
 	bool connected (const std::string&);
 	bool physically_connected (const std::string&);
-	int  get_connections (const std::string&, std::vector<std::string>&);
+	int  get_connections (const std::string&, std::vector<std::string>&, bool process_context_safe = true);
 
 	/* Naming */
 
diff --git a/libs/ardour/port_manager.cc b/libs/ardour/port_manager.cc
index c423ba65b8..f13637f6bb 100644
--- a/libs/ardour/port_manager.cc
+++ b/libs/ardour/port_manager.cc
@@ -751,7 +751,7 @@ PortManager::physically_connected (const string& port_name)
 }
 
 int
-PortManager::get_connections (const string& port_name, std::vector<std::string>& s)
+PortManager::get_connections (const string& port_name, std::vector<std::string>& s, bool process_context_safe)
 {
 	if (!_backend) {
 		s.clear ();
@@ -765,7 +765,7 @@ PortManager::get_connections (const string& port_name, std::vector<std::string>&
 		return 0;
 	}
 
-	return _backend->get_connections (handle, s);
+	return _backend->get_connections (handle, s, process_context_safe);
 }
 
 int
diff --git a/libs/ardour/session_midi.cc b/libs/ardour/session_midi.cc
index b1e8e7eb6c..2fc40386ca 100644
--- a/libs/ardour/session_midi.cc
+++ b/libs/ardour/session_midi.cc
@@ -744,7 +744,8 @@ Session::disconnect_port_for_rewire (std::string const& port) const
 	bool keep_ctrl = mpf & MidiPortControl;
 
 	vector<string> port_connections;
-	AudioEngine::instance()->get_connections (port, port_connections);
+	AudioEngine::instance()->get_connections (port, port_connections, false);
+
 	for (vector<string>::iterator i = port_connections.begin(); i != port_connections.end(); ++i) {
 
 		/* test if (*i) is a control-surface input port */