diff --git a/util/parse.cpp b/util/parse.cpp
index ed9db4bbf..f3f0279ce 100644
--- a/util/parse.cpp
+++ b/util/parse.cpp
@@ -20,21 +20,21 @@ Params ParseArgs(int argc, char** argv) {
 
 class NullEventHandler : public YAML::EventHandler {
  public:
-  virtual void OnDocumentStart(const YAML::Mark&) {}
-  virtual void OnDocumentEnd() {}
+  void OnDocumentStart(const YAML::Mark&) override {}
+  void OnDocumentEnd() override {}
 
-  virtual void OnNull(const YAML::Mark&, YAML::anchor_t) {}
-  virtual void OnAlias(const YAML::Mark&, YAML::anchor_t) {}
-  virtual void OnScalar(const YAML::Mark&, const std::string&, YAML::anchor_t,
-                        const std::string&) {}
+  void OnNull(const YAML::Mark&, YAML::anchor_t) override {}
+  void OnAlias(const YAML::Mark&, YAML::anchor_t) override {}
+  void OnScalar(const YAML::Mark&, const std::string&, YAML::anchor_t,
+                const std::string&) override {}
 
-  virtual void OnSequenceStart(const YAML::Mark&, const std::string&,
-                               YAML::anchor_t) {}
-  virtual void OnSequenceEnd() {}
+  void OnSequenceStart(const YAML::Mark&, const std::string&, YAML::anchor_t,
+                       YAML::EmitterStyle::value) override {}
+  void OnSequenceEnd() override {}
 
-  virtual void OnMapStart(const YAML::Mark&, const std::string&,
-                          YAML::anchor_t) {}
-  virtual void OnMapEnd() {}
+  void OnMapStart(const YAML::Mark&, const std::string&, YAML::anchor_t,
+                  YAML::EmitterStyle::value) override {}
+  void OnMapEnd() override {}
 };
 
 void parse(std::istream& input) {