diff --git a/samples/StandaloneApp/Pages/FetchData.cshtml b/samples/StandaloneApp/Pages/FetchData.cshtml
index 85123eb499..e32bafa791 100644
--- a/samples/StandaloneApp/Pages/FetchData.cshtml
+++ b/samples/StandaloneApp/Pages/FetchData.cshtml
@@ -44,7 +44,7 @@ else
 }
 
 @functions {
-    public DateTime StartDate { get; set; }
+    [Parameter] DateTime StartDate { get; set; }
 
     WeatherForecast[] forecasts;