diff --git a/libs/ardour/luabindings.cc b/libs/ardour/luabindings.cc
index 536c552bde..4dbcaeb360 100644
--- a/libs/ardour/luabindings.cc
+++ b/libs/ardour/luabindings.cc
@@ -1307,11 +1307,15 @@ LuaBindings::common (lua_State* L)
 		.addFunction ("name", &Plugin::name)
 		.addFunction ("maker", &Plugin::maker)
 		.addFunction ("parameter_count", &Plugin::parameter_count)
+		.addFunction ("parameter_label", &Plugin::parameter_label)
 		.addRefFunction ("nth_parameter", &Plugin::nth_parameter)
 		.addFunction ("preset_by_label", &Plugin::preset_by_label)
 		.addFunction ("preset_by_uri", &Plugin::preset_by_uri)
 		.addFunction ("load_preset", &Plugin::load_preset)
 		.addFunction ("parameter_is_input", &Plugin::parameter_is_input)
+		.addFunction ("parameter_is_output", &Plugin::parameter_is_output)
+		.addFunction ("parameter_is_control", &Plugin::parameter_is_control)
+		.addFunction ("parameter_is_audio", &Plugin::parameter_is_audio)
 		.addFunction ("get_docs", &Plugin::get_docs)
 		.addFunction ("get_info", &Plugin::get_info)
 		.addFunction ("get_parameter_docs", &Plugin::get_parameter_docs)