diff --git a/src/detail/ca-request-state.cpp b/src/detail/ca-request-state.cpp
index 68d189a..63ac317 100644
--- a/src/detail/ca-request-state.cpp
+++ b/src/detail/ca-request-state.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2021, Regents of the University of California.
+ * Copyright (c) 2017-2022, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -71,7 +71,7 @@
 operator<<(std::ostream& os, const RequestState& request)
 {
   os << "Request's CA name: " << request.caPrefix << "\n";
-  os << "Request's request ID: " << ndn::toHex(request.requestId.data(), request.requestId.size()) << "\n";
+  os << "Request's request ID: " << ndn::toHex(request.requestId) << "\n";
   os << "Request's status: " << statusToString(request.status) << "\n";
   os << "Request's challenge type: " << request.challengeType << "\n";
   if (request.challengeState) {