diff --git a/daemon/face/tcp-face.hpp b/daemon/face/tcp-face.hpp
index af45c6c..98593a0 100644
--- a/daemon/face/tcp-face.hpp
+++ b/daemon/face/tcp-face.hpp
@@ -21,6 +21,7 @@
 public:
   typedef boost::asio::ip::tcp protocol;
 
+  explicit
   TcpFace(const shared_ptr<protocol::socket>& socket);
 };