diff --git a/gtk2_ardour/ardour_ui.cc b/gtk2_ardour/ardour_ui.cc
index e1bcd06b7c..9c7a4a30dc 100644
--- a/gtk2_ardour/ardour_ui.cc
+++ b/gtk2_ardour/ardour_ui.cc
@@ -4000,7 +4000,7 @@ ARDOUR_UI::add_lua_script ()
 		return;
 	}
 
-	LuaScriptParamList lsp = LuaScripting::session_script_params (spi);
+	LuaScriptParamList lsp = LuaScriptParams::script_params (spi, "sess_params");
 	std::vector<std::string> reg = _session->registered_lua_functions ();
 
 	ScriptParameterDialog spd (_("Set Script Parameters"), spi, reg, lsp);
diff --git a/gtk2_ardour/luainstance.cc b/gtk2_ardour/luainstance.cc
index 0632199c08..41d81654bc 100644
--- a/gtk2_ardour/luainstance.cc
+++ b/gtk2_ardour/luainstance.cc
@@ -677,7 +677,7 @@ LuaInstance::interactive_add (LuaScriptInfo::ScriptType type, int id)
 		return false;
 	}
 
-	LuaScriptParamList lsp = LuaScripting::script_params (spi, "action_params");
+	LuaScriptParamList lsp = LuaScriptParams::script_params (spi, "action_params");
 
 	ScriptParameterDialog spd (_("Set Script Parameters"), spi, reg, lsp);
 	switch (spd.run ()) {
@@ -839,18 +839,9 @@ LuaInstance::lua_action (const int id, std::string& name, std::string& script, L
 		if (!lsi) {
 			return false;
 		}
-		args = LuaScripting::script_params (lsi, "action_params");
-		for (luabridge::Iterator i (static_cast<luabridge::LuaRef>(ref["args"])); !i.isNil (); ++i) {
-			if (!i.key ().isString ()) { assert(0); continue; }
-			std::string name = i.key ().cast<std::string> ();
-			std::string value = i.value ().cast<std::string> ();
-			for (LuaScriptParamList::const_iterator ii = args.begin(); ii != args.end(); ++ii) {
-				if ((*ii)->name == name) {
-					(*ii)->value = value;
-					break;
-				}
-			}
-		}
+		args = LuaScriptParams::script_params (lsi, "action_params");
+		luabridge::LuaRef rargs (ref["args"]);
+		LuaScriptParams::ref_to_params (args, &rargs);
 		return true;
 	} catch (luabridge::LuaException const& e) {
 		cerr << "LuaException:" << e.what () << endl;
@@ -1216,18 +1207,9 @@ LuaCallback::lua_slot (std::string& name, std::string& script, ActionHook& ah, A
 		if (!lsi) {
 			return false;
 		}
-		args = LuaScripting::script_params (lsi, "action_params");
-		for (luabridge::Iterator i (static_cast<luabridge::LuaRef>(ref["args"])); !i.isNil (); ++i) {
-			if (!i.key ().isString ()) { assert(0); continue; }
-			std::string name = i.key ().cast<std::string> ();
-			std::string value = i.value ().cast<std::string> ();
-			for (LuaScriptParamList::const_iterator ii = args.begin(); ii != args.end(); ++ii) {
-				if ((*ii)->name == name) {
-					(*ii)->value = value;
-					break;
-				}
-			}
-		}
+		args = LuaScriptParams::script_params (lsi, "action_params");
+		luabridge::LuaRef rargs (ref["args"]);
+		LuaScriptParams::ref_to_params (args, &rargs);
 		return true;
 	} catch (luabridge::LuaException const& e) {
 		cerr << "LuaException:" << e.what () << endl;
diff --git a/gtk2_ardour/luainstance.h b/gtk2_ardour/luainstance.h
index 9fb11c5d94..71c29741fa 100644
--- a/gtk2_ardour/luainstance.h
+++ b/gtk2_ardour/luainstance.h
@@ -8,6 +8,7 @@
 #include "pbd/xml++.h"
 
 #include "ardour/luascripting.h"
+#include "ardour/lua_script_params.h"
 #include "ardour/luabindings.h"
 #include "ardour/session_handle.h"