diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index b62c994ad..3477f6c46 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -161,9 +161,6 @@ struct DebugTrace {
     bool isError;
 };
 
-// Don't want Windows function
-#undef LookupPath
-
 class EvalState : public std::enable_shared_from_this<EvalState>
 {
 public:
diff --git a/src/libexpr/search-path.hh b/src/libexpr/search-path.hh
index 6a63f3730..acd843638 100644
--- a/src/libexpr/search-path.hh
+++ b/src/libexpr/search-path.hh
@@ -8,9 +8,6 @@
 
 namespace nix {
 
-// Do not want the windows macro (alias to `LookupPathA`)
-#undef LookupPath
-
 /**
  * A "search path" is a list of ways look for something, used with
  * `builtins.findFile` and `< >` lookup expressions.