diff --git a/src/node_buffer.cc b/src/node_buffer.cc
index 49df0b4284748e..0ee7883a5e5b67 100644
--- a/src/node_buffer.cc
+++ b/src/node_buffer.cc
@@ -98,7 +98,7 @@ class CallbackInfo : public Cleanable {
   CallbackInfo& operator=(const CallbackInfo&) = delete;
 
  private:
-  void Clean();
+  void Clean() override;
   inline void OnBackingStoreFree();
   inline void CallAndResetCallback();
   inline CallbackInfo(Environment* env,