diff --git a/src/ice_socket.h b/src/ice_socket.h
index e055f1479b51c923bf899870a56b851622d45df9..19fec6ccfe0ec8d95a303cf8eb8d08dccb15dec6 100644
--- a/src/ice_socket.h
+++ b/src/ice_socket.h
@@ -30,6 +30,7 @@
 #define ICE_SOCKET_H
 
 #include <memory>
+#include <functional>
 
 namespace ring {