diff --git a/tests/daemon/face/websocket-factory.t.cpp b/tests/daemon/face/websocket-factory.t.cpp
index 5043d87..aac1eca 100644
--- a/tests/daemon/face/websocket-factory.t.cpp
+++ b/tests/daemon/face/websocket-factory.t.cpp
@@ -28,6 +28,8 @@
 #include "face-system-fixture.hpp"
 #include "factory-test-common.hpp"
 
+#include <boost/lexical_cast.hpp>
+
 namespace nfd::tests {
 
 using face::WebSocketChannel;