diff --git a/src/scripting/lua_terrainfilter.cpp b/src/scripting/lua_terrainfilter.cpp
index 3a551a258af..64e9966ec0f 100644
--- a/src/scripting/lua_terrainfilter.cpp
+++ b/src/scripting/lua_terrainfilter.cpp
@@ -576,10 +576,9 @@ public:
 	std::unique_ptr<wfl::formula> formula_;
 };
 
-// todo: maybe invent a gerneral macro for this string_switch implementation.
+// todo: maybe invent a general macro for this string_switch implementation.
 enum filter_keys { F_AND, F_OR, F_NAND, F_NOR, F_X, F_Y, F_FIND_IN, F_ADJACENT, F_TERRAIN, F_RADIUS, F_FORMULA, F_CACHED };
-//todoc++14: std::unordered_map doesn'tsupport herterogrnous lookup.
-//todo consider renaming and -> all ,or ->any, nor -> none, nand -> notall
+// todo: c++20: perhaps enable heterogenous lookup.
 static const std::unordered_map<std::string, filter_keys> keys {
 	{ "all", F_AND },
 	{ "any", F_OR },