diff --git a/lib/src/sheet/src/models/sheet_store.model.dart b/lib/src/sheet/src/models/sheet_store.model.dart
index 96fc162..95e7a62 100644
--- a/lib/src/sheet/src/models/sheet_store.model.dart
+++ b/lib/src/sheet/src/models/sheet_store.model.dart
@@ -48,7 +48,7 @@ class SheetStore extends ChangeNotifier {
   }
 
   /// Return a stream builder for real-time value updates.
-  Widget builder(Widget child) {
+  Widget builder({required Widget child}) {
     return ListenableBuilder(listenable: this, builder: (_,__) => child);
   }
 }