diff --git a/tests/ping/server/ping-server.t.cpp b/tests/ping/server/ping-server.t.cpp
index 05a7d84..2efae0e 100644
--- a/tests/ping/server/ping-server.t.cpp
+++ b/tests/ping/server/ping-server.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2023,  Arizona Board of Regents.
+ * Copyright (c) 2014-2024,  Arizona Board of Regents.
  *
  * This file is part of ndn-tools (Named Data Networking Essential Tools).
  * See AUTHORS.md for complete list of ndn-tools authors and contributors.
@@ -37,7 +37,7 @@
   {
     Name name(pingOptions.prefix);
     name.append("ping")
-        .append(to_string(seq));
+        .append(std::to_string(seq));
 
     return Interest(name)
            .setMustBeFresh(true)