diff --git a/ptap/ptapui.cpp b/ptap/ptapui.cpp
index ec836d6..f465f0e 100644
--- a/ptap/ptapui.cpp
+++ b/ptap/ptapui.cpp
@@ -142,7 +142,7 @@ void PTapUI::InitWidgets()
 }
 
 struct FLV2PUi_PTapUI : LV2PUiFactory<FLV2PUi_PTapUI> {
-	/* virtual */ const char *GetUri() { return PTAP_URI "#X11UI"; }
+	/* virtual */ const char *GetUri() { return PTAP_URI; }
 
 	/* virtual */ LV2PUi *CreateInstance() { return new PTapUI(); }
 };
diff --git a/pui/lv2pui.cpp b/pui/lv2pui.cpp
index c1a2ff3..cfa84cd 100644
--- a/pui/lv2pui.cpp
+++ b/pui/lv2pui.cpp
@@ -4,6 +4,8 @@
 #include "pui.h"
 #include "lv2pui.h"
 
+static char s_lv2ui_uri[128];
+
 static void *lv2pui_thread(void *ptr)
 {
 	LV2PUi *lv2pui = (LV2PUi *)ptr;
@@ -62,10 +64,7 @@ static LV2UI_Handle lv2pui_instantiate(
 	LV2UI_Widget *widget,
 	const LV2_Feature *const *features)
 {
-	char uri[128];
-	snprintf(uri, sizeof uri, "%s#X11UI", plugin_uri);
-
-	LV2PUi *lv2pui = LV2PUiFactoryBase::CreateInstance(uri);
+	LV2PUi *lv2pui = LV2PUiFactoryBase::CreateInstance(plugin_uri);
 	if (!lv2pui) return NULL;
 
 	lv2pui->Instantiate(descriptor, bundle_path, write_function, controller, widget, features);
@@ -124,7 +123,7 @@ static const void *lv2pui_extension_data(const char *uri)
 }
 
 static LV2UI_Descriptor s_lv2ui_descriptor = {
-	NULL,
+	s_lv2ui_uri,
 	&lv2pui_instantiate,
 	&lv2pui_cleanup,
 	&lv2pui_port_event,
@@ -136,6 +135,6 @@ const LV2UI_Descriptor *lv2ui_descriptor(uint32_t index)
 	const char *uri = LV2PUiFactoryBase::GetUri(index);
 	if (!uri) return NULL;
 
-	s_lv2ui_descriptor.URI = uri;
+	snprintf(s_lv2ui_uri, sizeof s_lv2ui_uri, "%s#%s", uri, "X11UI");
 	return &s_lv2ui_descriptor;
 }