diff --git a/src/security/tls_session.h b/src/security/tls_session.h
index 58211598315f95bc5527aef880ea50189f5220e3..2417257b4d2220757608868c6ab19fd20b2e713e 100644
--- a/src/security/tls_session.h
+++ b/src/security/tls_session.h
@@ -114,7 +114,7 @@ public:
 
     /// Request TLS thread to stop and quit.
     /// \note IO operations return error after this call.
-    void shutdown();
+    void shutdown() override;
 
     void setOnRecv(RecvCb&& cb) override {
         (void)cb;