diff --git a/src/nix/eval.cc b/src/nix/eval.cc
index 494735516..f8a9da736 100644
--- a/src/nix/eval.cc
+++ b/src/nix/eval.cc
@@ -78,14 +78,14 @@ struct CmdEval : MixJSON, InstallableValueCommand, MixReadOnlyOption
             if (pathExists(*writeTo))
                 throw Error("path '%s' already exists", *writeTo);
 
-            std::function<void(Value & v, const PosIdx pos, const Path & path)> recurse;
+            std::function<void(Value & v, const PosIdx pos, const std::filesystem::path & path)> recurse;
 
-            recurse = [&](Value & v, const PosIdx pos, const Path & path)
+            recurse = [&](Value & v, const PosIdx pos, const std::filesystem::path & path)
             {
                 state->forceValue(v, pos);
                 if (v.type() == nString)
                     // FIXME: disallow strings with contexts?
-                    writeFile(path, v.string_view());
+                    writeFile(path.string(), v.string_view());
                 else if (v.type() == nAttrs) {
                     if (mkdir(path.c_str()
 #ifndef _WIN32 // TODO abstract mkdir perms for Windows
@@ -98,7 +98,7 @@ struct CmdEval : MixJSON, InstallableValueCommand, MixReadOnlyOption
                         try {
                             if (name == "." || name == "..")
                                 throw Error("invalid file name '%s'", name);
-                            recurse(*attr.value, attr.pos, concatStrings(path, "/", name));
+                            recurse(*attr.value, attr.pos, path / name);
                         } catch (Error & e) {
                             e.addTrace(
                                 state->positions[attr.pos],
diff --git a/src/nix/flake.cc b/src/nix/flake.cc
index 3f9f8f99b..7cfbf48a1 100644
--- a/src/nix/flake.cc
+++ b/src/nix/flake.cc
@@ -18,6 +18,7 @@
 #include "markdown.hh"
 #include "users.hh"
 
+#include <filesystem>
 #include <nlohmann/json.hpp>
 #include <iomanip>
 
@@ -870,27 +871,27 @@ struct CmdFlakeInitCommon : virtual Args, EvalCommand
                 "If you've set '%s' to a string, try using a path instead.",
                 templateDir, templateDirAttr->getAttrPathStr()).debugThrow();
 
-        std::vector<Path> changedFiles;
-        std::vector<Path> conflictedFiles;
+        std::vector<std::filesystem::path> changedFiles;
+        std::vector<std::filesystem::path> conflictedFiles;
 
-        std::function<void(const Path & from, const Path & to)> copyDir;
-        copyDir = [&](const Path & from, const Path & to)
+        std::function<void(const std::filesystem::path & from, const std::filesystem::path & to)> copyDir;
+        copyDir = [&](const std::filesystem::path & from, const std::filesystem::path & to)
         {
             createDirs(to);
 
             for (auto & entry : std::filesystem::directory_iterator{from}) {
                 checkInterrupt();
-                auto from2 = entry.path().string();
-                auto to2 = to + "/" + entry.path().filename().string();
-                auto st = lstat(from2);
-                if (S_ISDIR(st.st_mode))
+                auto from2 = entry.path();
+                auto to2 = to / entry.path().filename();
+                auto st = entry.symlink_status();
+                if (std::filesystem::is_directory(st))
                     copyDir(from2, to2);
-                else if (S_ISREG(st.st_mode)) {
+                else if (std::filesystem::is_regular_file(st)) {
                     auto contents = readFile(from2);
                     if (pathExists(to2)) {
                         auto contents2 = readFile(to2);
                         if (contents != contents2) {
-                            printError("refusing to overwrite existing file '%s'\n please merge it manually with '%s'", to2, from2);
+                            printError("refusing to overwrite existing file '%s'\n please merge it manually with '%s'", to2.string(), from2.string());
                             conflictedFiles.push_back(to2);
                         } else {
                             notice("skipping identical file: %s", from2);
@@ -899,11 +900,11 @@ struct CmdFlakeInitCommon : virtual Args, EvalCommand
                     } else
                         writeFile(to2, contents);
                 }
-                else if (S_ISLNK(st.st_mode)) {
+                else if (std::filesystem::is_symlink(st)) {
                     auto target = readLink(from2);
                     if (pathExists(to2)) {
                         if (readLink(to2) != target) {
-                            printError("refusing to overwrite existing file '%s'\n please merge it manually with '%s'", to2, from2);
+                            printError("refusing to overwrite existing file '%s'\n please merge it manually with '%s'", to2.string(), from2.string());
                             conflictedFiles.push_back(to2);
                         } else {
                             notice("skipping identical file: %s", from2);