diff --git a/src/list_instance.hpp b/src/list_instance.hpp
new file mode 100644
index 0000000..3fa19c9
--- /dev/null
+++ b/src/list_instance.hpp
@@ -0,0 +1,12 @@
+/*
+ * Copyright (C) 2020 CESNET, https://photonics.cesnet.cz/
+ *
+ * Written by Václav Kubernát <kubernat@cesnet.cz>
+ *
+*/
+#pragma once
+#include <map>
+#include <string>
+#include "ast_values.hpp"
+
+using ListInstance = std::map<std::string, leaf_data_>;