diff --git a/src/OpenIddict.Mvc/OpenIddictController.cs b/src/OpenIddict.Mvc/OpenIddictController.cs
index 7d9ea631..b01d2d6d 100644
--- a/src/OpenIddict.Mvc/OpenIddictController.cs
+++ b/src/OpenIddict.Mvc/OpenIddictController.cs
@@ -65,7 +65,7 @@ namespace OpenIddict.Mvc {
             if (!User.Identities.Any(identity => identity.IsAuthenticated)) {
                 return new ChallengeResult(new AuthenticationProperties {
                     RedirectUri = Url.Action(nameof(Authorize), new {
-                        unique_id = request.GetUniqueIdentifier()
+                        request_id = request.GetRequestIdentifier()
                     })
                 });
             }