diff --git a/daemon/table/network-region-table.hpp b/daemon/table/network-region-table.hpp
index b4ee652..c7445ad 100644
--- a/daemon/table/network-region-table.hpp
+++ b/daemon/table/network-region-table.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  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,
@@ -28,6 +28,8 @@
 
 #include "core/common.hpp"
 
+#include <set>
+
 namespace nfd {
 
 /** \brief Stores a collection of producer region names.