diff --git a/packages/flutter_tools/lib/src/build_system/targets/assets.dart b/packages/flutter_tools/lib/src/build_system/targets/assets.dart
index 68a4cd0257..1e212b9b0d 100644
--- a/packages/flutter_tools/lib/src/build_system/targets/assets.dart
+++ b/packages/flutter_tools/lib/src/build_system/targets/assets.dart
@@ -101,7 +101,11 @@ Future<Depfile> copyAssets(Environment environment, Directory outputDirectory, {
             outputPath: file.path,
             relativePath: entry.key,
           )) {
-            await (content.file as File).copy(file.path);
+             // Not using File.copy because it preserves permissions.
+             final sourceFile = content.file as File;
+             final destinationFile = file;
+ 
+             await destinationFile.writeAsBytes(await sourceFile.readAsBytes(), flush: true);
           }
         } else {
           await file.writeAsBytes(await entry.value.contentsAsBytes());