diff --git a/gtk2_ardour/engine_dialog.cc b/gtk2_ardour/engine_dialog.cc
index 57a30abc99..31738bed15 100644
--- a/gtk2_ardour/engine_dialog.cc
+++ b/gtk2_ardour/engine_dialog.cc
@@ -779,6 +779,7 @@ EngineControl::update_sensitivity ()
 
 	bool valid = true;
 	size_t devices_available = 0;
+	bool engine_running = ARDOUR::AudioEngine::instance()->running();
 
 	if (backend->use_separate_input_and_output_devices ()) {
 		devices_available += get_popdown_string_count (input_device_combo);
@@ -796,12 +797,12 @@ EngineControl::update_sensitivity ()
 	} else {
 		input_latency.set_sensitive (true);
 		output_latency.set_sensitive (true);
-		input_channels.set_sensitive (true);
-		output_channels.set_sensitive (true);
+		input_channels.set_sensitive (!engine_running);
+		output_channels.set_sensitive (!engine_running);
 	}
 
 	if (get_popdown_string_count (buffer_size_combo) > 0) {
-		if (!ARDOUR::AudioEngine::instance()->running()) {
+		if (!engine_running) {
 			buffer_size_combo.set_sensitive (valid);
 		} else if (backend->can_change_sample_rate_when_running()) {
 			buffer_size_combo.set_sensitive (valid || !_have_control);
@@ -827,7 +828,7 @@ EngineControl::update_sensitivity ()
 
 	if (get_popdown_string_count (sample_rate_combo) > 0) {
 		bool allow_to_set_rate = false;
-		if (!ARDOUR::AudioEngine::instance()->running()) {
+		if (!engine_running) {
 			if (!ARDOUR_UI::instance()->session_loaded) {
 				// engine is not running, no session loaded -> anything goes.
 				allow_to_set_rate = true;
@@ -843,7 +844,7 @@ EngineControl::update_sensitivity ()
 	}
 
 	if (get_popdown_string_count (nperiods_combo) > 0) {
-		if (!ARDOUR::AudioEngine::instance()->running()) {
+		if (!engine_running) {
 			nperiods_combo.set_sensitive (true);
 		} else {
 			nperiods_combo.set_sensitive (false);
@@ -855,7 +856,7 @@ EngineControl::update_sensitivity ()
 	if (_have_control) {
 		start_stop_button.set_sensitive(true);
 		start_stop_button.show();
-		if (ARDOUR::AudioEngine::instance()->running()) {
+		if (engine_running) {
 			start_stop_button.set_text("Stop");
 			update_devices_button.set_sensitive(false);
 			use_buffered_io_button.set_sensitive(false);
@@ -883,7 +884,7 @@ EngineControl::update_sensitivity ()
 		start_stop_button.hide();
 	}
 
-	if (ARDOUR::AudioEngine::instance()->running() && _have_control) {
+	if (engine_running && _have_control) {
 		input_device_combo.set_sensitive (false);
 		output_device_combo.set_sensitive (false);
 		device_combo.set_sensitive (false);
@@ -898,6 +899,8 @@ EngineControl::update_sensitivity ()
 			driver_combo.set_sensitive (false);
 		}
 	}
+
+	midi_option_combo.set_sensitive (!engine_running);
 }
 
 void