diff --git a/tools/ndn-autoconfig/multicast-discovery.cpp b/tools/ndn-autoconfig/multicast-discovery.cpp
index 61312cd..dca08fc 100644
--- a/tools/ndn-autoconfig/multicast-discovery.cpp
+++ b/tools/ndn-autoconfig/multicast-discovery.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2023,  Regents of the University of California,
+ * Copyright (c) 2014-2024,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -55,7 +55,7 @@
     filter,
     [this] (const auto& dataset) { registerHubDiscoveryPrefix(dataset); },
     [this] (uint32_t code, const std::string& reason) {
-      fail("Error " + to_string(code) + " when querying multi-access faces: " + reason);
+      fail("Error " + std::to_string(code) + " when querying multi-access faces: " + reason);
     });
 }
 
@@ -119,7 +119,7 @@
     parameters,
     [this] (const auto&) { requestHubData(); },
     [this] (const auto& resp) {
-      fail("Error " + to_string(resp.getCode()) + " when setting multicast strategy: " + resp.getText());
+      fail("Error " + std::to_string(resp.getCode()) + " when setting multicast strategy: " + resp.getText());
     });
 }