diff --git a/src/Skoruba.Duende.IdentityServer.STS.Identity/ViewModels/Manage/EnableAuthenticatorViewModel.cs b/src/Skoruba.Duende.IdentityServer.STS.Identity/ViewModels/Manage/EnableAuthenticatorViewModel.cs
index a844af95b..9edcd12ec 100644
--- a/src/Skoruba.Duende.IdentityServer.STS.Identity/ViewModels/Manage/EnableAuthenticatorViewModel.cs
+++ b/src/Skoruba.Duende.IdentityServer.STS.Identity/ViewModels/Manage/EnableAuthenticatorViewModel.cs
@@ -12,9 +12,9 @@ public class EnableAuthenticatorViewModel
         public string Code { get; set; }
 
         [BindNever]
-        public string SharedKey { get; set; }
+        public string? SharedKey { get; set; }
 
         [BindNever]
-        public string AuthenticatorUri { get; set; }
+        public string? AuthenticatorUri { get; set; }
     }
 }