diff --git a/ptap/manifest.ttl b/ptap/manifest.ttl
index 25e9819..353e6b0 100644
--- a/ptap/manifest.ttl
+++ b/ptap/manifest.ttl
@@ -12,6 +12,10 @@
   a ui:X11UI;
   ui:binary <ptapui.so>.
 
+<urn:fuzzle:ptap#ExtUI>
+  a ui:external ;
+  ui:binary <ptapui.so> .
+
 <default.ttl>
   a pset:Preset ;
   rdfs:seeAlso <default.ttl> ;
diff --git a/ptap/ptap_helper.cpp b/ptap/ptap_helper.cpp
index 9664f44..c811f3b 100644
--- a/ptap/ptap_helper.cpp
+++ b/ptap/ptap_helper.cpp
@@ -57,6 +57,7 @@ static void addttl(const char *file)
 		"  doap:name \"PTap\" ;\n"
 		"  doap:license <http://usefulinc.com/doap/licenses/gpl> ;\n"
 		"  ui:ui <" PTAP_URI "#X11UI> ;\n"
+		"  ui:ui <" PTAP_URI "#ExtUI> ;\n"
 		"  lv2:port\n"
 		, fp);