diff --git a/src/libflake/config.cc b/src/libflake/config.cc
index c248ed0a6..fd0e9c75f 100644
--- a/src/libflake/config.cc
+++ b/src/libflake/config.cc
@@ -31,9 +31,9 @@ namespace nix::flake {
 // setting name -> setting value -> allow or ignore.
 typedef std::map<std::string, std::map<std::string, bool>> TrustedList;
 
-Path trustedListPath()
+std::filesystem::path trustedListPath()
 {
-    return getDataDir() + "/trusted-settings.json";
+    return getDataDir() / "trusted-settings.json";
 }
 
 static TrustedList readTrustedList()
@@ -48,7 +48,7 @@ static TrustedList readTrustedList()
 static void writeTrustedList(const TrustedList & trustedList)
 {
     auto path = trustedListPath();
-    createDirs(dirOf(path));
+    createDirs(path.parent_path());
     writeFile(path, nlohmann::json(trustedList).dump());
 }
 
diff --git a/src/libflake/flakeref.cc b/src/libflake/flakeref.cc
index 8c955c72d..0a55ac35c 100644
--- a/src/libflake/flakeref.cc
+++ b/src/libflake/flakeref.cc
@@ -74,7 +74,7 @@ FlakeRef::resolve(const fetchers::Settings & fetchSettings, Store & store, fetch
 FlakeRef parseFlakeRef(
     const fetchers::Settings & fetchSettings,
     const std::string & url,
-    const std::optional<Path> & baseDir,
+    const std::optional<std::filesystem::path> & baseDir,
     bool allowMissing,
     bool isFlake,
     bool preserveRelativePaths)
@@ -101,7 +101,7 @@ fromParsedURL(const fetchers::Settings & fetchSettings, ParsedURL && parsedURL,
 std::pair<FlakeRef, std::string> parsePathFlakeRefWithFragment(
     const fetchers::Settings & fetchSettings,
     const std::string & url,
-    const std::optional<Path> & baseDir,
+    const std::optional<std::filesystem::path> & baseDir,
     bool allowMissing,
     bool isFlake,
     bool preserveRelativePaths)
@@ -121,7 +121,7 @@ std::pair<FlakeRef, std::string> parsePathFlakeRefWithFragment(
            to 'baseDir'). If so, search upward to the root of the
            repo (i.e. the directory containing .git). */
 
-        path = absPath(path, baseDir, true);
+        path = absPath(path, baseDir->string(), true);
 
         if (isFlake) {
 
@@ -243,7 +243,7 @@ parseFlakeIdRef(const fetchers::Settings & fetchSettings, const std::string & ur
 std::optional<std::pair<FlakeRef, std::string>> parseURLFlakeRef(
     const fetchers::Settings & fetchSettings,
     const std::string & url,
-    const std::optional<Path> & baseDir,
+    const std::optional<std::filesystem::path> & baseDir,
     bool isFlake)
 {
     try {
@@ -252,7 +252,7 @@ std::optional<std::pair<FlakeRef, std::string>> parseURLFlakeRef(
             /* Here we know that the path must not contain encoded '/' or NUL bytes. */
             auto path = renderUrlPathEnsureLegal(parsed.path);
             if (!isAbsolute(path))
-                parsed.path = splitString<std::vector<std::string>>(absPath(path, *baseDir), "/");
+                parsed.path = splitString<std::vector<std::string>>(absPath(path, baseDir->string()), "/");
         }
         return fromParsedURL(fetchSettings, std::move(parsed), isFlake);
     } catch (BadURL &) {
@@ -263,7 +263,7 @@ std::optional<std::pair<FlakeRef, std::string>> parseURLFlakeRef(
 std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
     const fetchers::Settings & fetchSettings,
     const std::string & url,
-    const std::optional<Path> & baseDir,
+    const std::optional<std::filesystem::path> & baseDir,
     bool allowMissing,
     bool isFlake,
     bool preserveRelativePaths)
@@ -347,7 +347,7 @@ FlakeRef FlakeRef::canonicalize() const
 std::tuple<FlakeRef, std::string, ExtendedOutputsSpec> parseFlakeRefWithFragmentAndExtendedOutputsSpec(
     const fetchers::Settings & fetchSettings,
     const std::string & url,
-    const std::optional<Path> & baseDir,
+    const std::optional<std::filesystem::path> & baseDir,
     bool allowMissing,
     bool isFlake)
 {
diff --git a/src/libflake/include/nix/flake/flake.hh b/src/libflake/include/nix/flake/flake.hh
index 09255fbef..c2d597ac1 100644
--- a/src/libflake/include/nix/flake/flake.hh
+++ b/src/libflake/include/nix/flake/flake.hh
@@ -200,7 +200,7 @@ struct LockFlags
     /**
      * The path to a lock file to write to instead of the `flake.lock` file in the top-level flake
      */
-    std::optional<Path> outputLockFilePath;
+    std::optional<std::filesystem::path> outputLockFilePath;
 
     /**
      * Flake inputs to be overridden.
diff --git a/src/libflake/include/nix/flake/flakeref.hh b/src/libflake/include/nix/flake/flakeref.hh
index 91c93af41..05c21bd1c 100644
--- a/src/libflake/include/nix/flake/flakeref.hh
+++ b/src/libflake/include/nix/flake/flakeref.hh
@@ -95,7 +95,7 @@ std::ostream & operator<<(std::ostream & str, const FlakeRef & flakeRef);
 FlakeRef parseFlakeRef(
     const fetchers::Settings & fetchSettings,
     const std::string & url,
-    const std::optional<Path> & baseDir = {},
+    const std::optional<std::filesystem::path> & baseDir = {},
     bool allowMissing = false,
     bool isFlake = true,
     bool preserveRelativePaths = false);
@@ -106,7 +106,7 @@ FlakeRef parseFlakeRef(
 std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
     const fetchers::Settings & fetchSettings,
     const std::string & url,
-    const std::optional<Path> & baseDir = {},
+    const std::optional<std::filesystem::path> & baseDir = {},
     bool allowMissing = false,
     bool isFlake = true,
     bool preserveRelativePaths = false);
@@ -117,7 +117,7 @@ std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
 std::tuple<FlakeRef, std::string, ExtendedOutputsSpec> parseFlakeRefWithFragmentAndExtendedOutputsSpec(
     const fetchers::Settings & fetchSettings,
     const std::string & url,
-    const std::optional<Path> & baseDir = {},
+    const std::optional<std::filesystem::path> & baseDir = {},
     bool allowMissing = false,
     bool isFlake = true);