diff --git a/packages/mason/lib/src/bricks_json.dart b/packages/mason/lib/src/bricks_json.dart
index 562843dfa..05abe1732 100644
--- a/packages/mason/lib/src/bricks_json.dart
+++ b/packages/mason/lib/src/bricks_json.dart
@@ -440,11 +440,13 @@ class BricksJson {
     if (environment.containsKey('MASON_CACHE')) {
       return Directory(environment['MASON_CACHE']!);
     } else if (isWindows) {
+      const longPathPrefix = r'\\?\';
       final appData = environment['APPDATA']!;
-      final appDataCacheDir = Directory(p.join(appData, 'Mason', 'Cache'));
-      if (appDataCacheDir.existsSync()) return Directory(appDataCacheDir.path);
+      final appDataCacheDir =
+          Directory(longPathPrefix + p.join(appData, 'Mason', 'Cache'));
+      if (appDataCacheDir.existsSync()) return appDataCacheDir;
       final localAppData = environment['LOCALAPPDATA']!;
-      return Directory(p.join(localAppData, 'Mason', 'Cache'));
+      return Directory(longPathPrefix + p.join(localAppData, 'Mason', 'Cache'));
     } else {
       return Directory(p.join(environment['HOME']!, '.mason-cache'));
     }
diff --git a/packages/mason/lib/src/path.dart b/packages/mason/lib/src/path.dart
index 7b616b1e7..1a589b9fb 100644
--- a/packages/mason/lib/src/path.dart
+++ b/packages/mason/lib/src/path.dart
@@ -7,8 +7,8 @@ import 'package:path/path.dart' as p;
 /// However, it does not change the ASCII case of the path.
 /// See https://github.com/dart-lang/path/issues/102.
 String canonicalize(String path) {
-  return p.normalize(p.absolute(path)).replaceAll(r'\', '/');
+  return p.normalize(p.absolute(path));
 }
 
 /// Normalizes the [path].
-String normalize(String path) => p.normalize(path).replaceAll(r'\', '/');
+String normalize(String path) => p.normalize(path);
diff --git a/packages/mason/test/src/bricks_json_test.dart b/packages/mason/test/src/bricks_json_test.dart
index 8558e3c5e..4f205c93a 100644
--- a/packages/mason/test/src/bricks_json_test.dart
+++ b/packages/mason/test/src/bricks_json_test.dart
@@ -717,7 +717,10 @@ environment:
         )..createSync(recursive: true);
         BricksJson.testEnvironment = {'APPDATA': directory.path};
         BricksJson.testIsWindows = true;
-        expect(BricksJson.rootDir.path, equals(appDataCacheDirectory.path));
+        expect(
+          BricksJson.rootDir.path,
+          equals('${r'\\?\'}${appDataCacheDirectory.path}'),
+        );
       });
 
       test(
@@ -732,7 +735,10 @@ environment:
           'LOCALAPPDATA': directory.path
         };
         BricksJson.testIsWindows = true;
-        expect(BricksJson.rootDir.path, equals(appDataCacheDirectory.path));
+        expect(
+          BricksJson.rootDir.path,
+          equals('${r'\\?\'}${appDataCacheDirectory.path}'),
+        );
       });
 
       test('uses HOME by default', () {