diff --git a/policy_manager/policy.h b/policy_manager/policy.h
index 762b9a5..5896fe7 100644
--- a/policy_manager/policy.h
+++ b/policy_manager/policy.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_POLICY_MANAGER_POLICY_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_H_
 
 #include "update_engine/policy_manager/evaluation_context.h"
 #include "update_engine/policy_manager/state.h"
@@ -49,4 +49,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_H_