diff --git a/mock_process_killer.h b/mock_process_killer.h
index 6399f34..6dae6fd 100644
--- a/mock_process_killer.h
+++ b/mock_process_killer.h
@@ -14,7 +14,7 @@
 class MockProcessKiller : public ProcessKiller {
  public:
   MockProcessKiller();
-  virtual ~MockProcessKiller();
+  ~MockProcessKiller() override;
 
   MOCK_METHOD2(Wait, bool(int pid, const base::Closure &callback));
   MOCK_METHOD2(Kill, void(int pid, const base::Closure &callback));