diff --git a/test/test_natpmp.cpp b/test/test_natpmp.cpp
index b921f33d9..ef089e46c 100644
--- a/test/test_natpmp.cpp
+++ b/test/test_natpmp.cpp
@@ -1,5 +1,6 @@
 #include "libtorrent/natpmp.hpp"
 #include "libtorrent/socket.hpp"
+#include "libtorrent/socket_io.hpp"
 #include "libtorrent/connection_queue.hpp"
 #include <boost/bind.hpp>
 #include <boost/ref.hpp>