diff --git a/cs3/app/provider/v1beta1/provider_api.proto b/cs3/app/provider/v1beta1/provider_api.proto
index e266be5..7aa5c62 100644
--- a/cs3/app/provider/v1beta1/provider_api.proto
+++ b/cs3/app/provider/v1beta1/provider_api.proto
@@ -94,4 +94,7 @@ message OpenInAppResponse {
   // OPTIONAL.
   // A reason in case the requested view_mode was overridden due to e.g. external locks.
   string forced_view_mode_reason = 4;
+  // OPTIONAL.
+  // An alternate app name to be given as hint, should the resource be found to have been locked by it.
+  string app_for_edit = 5;
 }