diff --git a/daemon/face/protocol-factory.hpp b/daemon/face/protocol-factory.hpp
index ed87de3..50023cc 100644
--- a/daemon/face/protocol-factory.hpp
+++ b/daemon/face/protocol-factory.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -133,7 +133,7 @@
   struct CreateFaceRequest
   {
     FaceUri remoteUri;
-    optional<FaceUri> localUri;
+    std::optional<FaceUri> localUri;
     FaceParams params;
   };