diff --git a/test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.cpp b/test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.cpp
index 305317ffffa..a51977b578a 100644
--- a/test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.cpp
+++ b/test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.cpp
@@ -22,7 +22,7 @@
  */
 
 #include <stdlib.h>
-#include "nsk_mutex.h"
+#include "nsk_mutex.hpp"
 
 extern "C" {
 
diff --git a/test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.h b/test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.hpp
similarity index 92%
rename from test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.h
rename to test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.hpp
index 322b6a54dde..629a4079b70 100644
--- a/test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.h
+++ b/test/hotspot/jtreg/vmTestbase/nsk/share/native/nsk_mutex.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -21,8 +21,8 @@
  * questions.
  */
 
-#ifndef NSK_MUTEX_H
-#define NSK_MUTEX_H
+#ifndef NSK_MUTEX_HPP
+#define NSK_MUTEX_HPP
 
 extern "C" {