diff --git a/daemon/face/websocket-transport.cpp b/daemon/face/websocket-transport.cpp
index cf3da37..6423330 100644
--- a/daemon/face/websocket-transport.cpp
+++ b/daemon/face/websocket-transport.cpp
@@ -106,6 +106,8 @@
 {
   NFD_LOG_FACE_TRACE(__func__);
 
+  ++this->nOutPings;
+
   websocketpp::lib::error_code error;
   m_server.ping(m_handle, "NFD-WebSocket", error);
   if (error)
@@ -118,6 +120,8 @@
 WebSocketTransport::handlePong()
 {
   NFD_LOG_FACE_TRACE(__func__);
+
+  ++this->nInPongs;
 }
 
 void