diff --git a/utils.h b/utils.h
index a84f512..f404653 100644
--- a/utils.h
+++ b/utils.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_UTILS_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H_
 
 #include <algorithm>
 #include <errno.h>
@@ -609,4 +609,4 @@
 
 
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H_