diff --git a/googlemock/docs/cook_book.md b/googlemock/docs/cook_book.md
index 3033446e..c29d4c32 100644
--- a/googlemock/docs/cook_book.md
+++ b/googlemock/docs/cook_book.md
@@ -3078,7 +3078,7 @@ class MockFoo : public Foo {
   ...
   // Add the following two lines to the mock class.
   MOCK_METHOD(void, Die, ());
-  virtual ~MockFoo() { Die(); }
+  ~MockFoo() override { Die(); }
 };
 ```