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 5f458bd53e..7a6c59f98d 100644
--- a/packages/flutter_tools/lib/src/build_system/targets/assets.dart
+++ b/packages/flutter_tools/lib/src/build_system/targets/assets.dart
@@ -128,7 +128,11 @@ Future<Depfile> copyAssets(
               break;
           }
           if (doCopy) {
-            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());