diff --git a/src/Microsoft.Identity.Web/TempDataLoginErrorAccessor.cs b/src/Microsoft.Identity.Web/TempDataLoginErrorAccessor.cs
index da5e6812f..48d10acee 100644
--- a/src/Microsoft.Identity.Web/TempDataLoginErrorAccessor.cs
+++ b/src/Microsoft.Identity.Web/TempDataLoginErrorAccessor.cs
@@ -59,7 +59,7 @@ public void SetMessage(HttpContext context, string? message)
             {
                 _tempData = _factory.GetTempData(context);
 
-                _tempData.Add(Name, message);
+                _tempData[Name] = message;
                 _tempData.Save();
             }
         }