diff --git a/gtk2_ardour/lv2_plugin_ui.cc b/gtk2_ardour/lv2_plugin_ui.cc
index 7524b6b5de..f72e7916c0 100644
--- a/gtk2_ardour/lv2_plugin_ui.cc
+++ b/gtk2_ardour/lv2_plugin_ui.cc
@@ -267,6 +267,7 @@ LV2PluginUI::lv2ui_instantiate(const std::string& title)
 	}
 
 	if (_lv2->has_message_output()) {
+		_lv2->enable_ui_emmission();
 		ARDOUR_UI::instance()->RapidScreenUpdate.connect(
 			sigc::mem_fun(*this, &LV2PluginUI::update_timeout));
 	}
diff --git a/libs/ardour/ardour/lv2_plugin.h b/libs/ardour/ardour/lv2_plugin.h
index cf764b34d2..8ae9016bb2 100644
--- a/libs/ardour/ardour/lv2_plugin.h
+++ b/libs/ardour/ardour/lv2_plugin.h
@@ -125,6 +125,7 @@ class LV2Plugin : public ARDOUR::Plugin
 	                           uint32_t    format,
 	                           const void* buffer);
 
+	void enable_ui_emmission();
 	void emit_to_ui(void* controller, UIMessageSink sink);
 
 	static URIMap _uri_map;
diff --git a/libs/ardour/lv2_plugin.cc b/libs/ardour/lv2_plugin.cc
index d74d23acc2..4a21e84628 100644
--- a/libs/ardour/lv2_plugin.cc
+++ b/libs/ardour/lv2_plugin.cc
@@ -819,12 +819,16 @@ LV2Plugin::write_to_ui(uint32_t index,
                        uint32_t protocol,
                        uint32_t size,
                        uint8_t* body)
+{
+	write_to(_to_ui, index, protocol, size, body);
+}
+
+void
+LV2Plugin::enable_ui_emmission()
 {
 	if (!_to_ui) {
 		_to_ui = new RingBuffer<uint8_t>(4096);
 	}
-
-	write_to(_to_ui, index, protocol, size, body);
 }
 
 void
@@ -1156,7 +1160,7 @@ LV2Plugin::connect_and_run(BufferSet& bufs,
 		}
 
 		// Write messages to UI
-		if ((flags & PORT_OUTPUT) && (flags & PORT_MESSAGE)) {
+		if (_to_ui && (flags & PORT_OUTPUT) && (flags & PORT_MESSAGE)) {
 			LV2_Evbuf* buf = _ev_buffers[port_index];
 			for (LV2_Evbuf_Iterator i = lv2_evbuf_begin(buf);
 			     lv2_evbuf_is_valid(i);