diff --git a/lib/tun2/server.go b/lib/tun2/server.go
index 45c3eb6..96dc5b4 100644
--- a/lib/tun2/server.go
+++ b/lib/tun2/server.go
@@ -390,6 +390,13 @@ func (s *Server) RoundTrip(req *http.Request) (*http.Response, error) {
 	}
 
 	if len(conns) == 0 {
+		ln.Error(errors.New("no backend connected"), ln.F{
+			"action": "no_backend_connected",
+			"remote": req.RemoteAddr,
+			"host":   req.Host,
+			"uri":    req.RequestURI,
+		})
+
 		return nil, errors.New("no backend connected")
 	}