diff --git a/engine/src/flutter/examples/mine_digger/lib/main.dart b/engine/src/flutter/examples/mine_digger/lib/main.dart
index 3b8e561f66c..1384732aacd 100644
--- a/engine/src/flutter/examples/mine_digger/lib/main.dart
+++ b/engine/src/flutter/examples/mine_digger/lib/main.dart
@@ -142,7 +142,7 @@ class MineDiggerApp extends App {
         new Row(
           row,
           justifyContent: FlexJustifyContent.center,
-          key: new Key.stringify(iy)
+          key: new ValueKey<int>(iy)
         )
       );
     }