diff --git a/hwid_override.h b/hwid_override.h
index 8f8dbc6..4d9bf9b 100644
--- a/hwid_override.h
+++ b/hwid_override.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H_
 
 #include <map>
 #include <string>
@@ -30,4 +30,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H_