diff --git a/policy_manager/boxed_value.h b/policy_manager/boxed_value.h
index f0b1ec2..0d44c3c 100644
--- a/policy_manager/boxed_value.h
+++ b/policy_manager/boxed_value.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_BOXED_VALUE_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_BOXED_VALUE_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_BOXED_VALUE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_BOXED_VALUE_H_
 
 #include <base/basictypes.h>
 
@@ -87,4 +87,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_BOXED_VALUE_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_BOXED_VALUE_H_
diff --git a/policy_manager/chromeos_policy.h b/policy_manager/chromeos_policy.h
index 1eede27..93d3723 100644
--- a/policy_manager/chromeos_policy.h
+++ b/policy_manager/chromeos_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_CHROMEOS_POLICY_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_CHROMEOS_POLICY_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_CHROMEOS_POLICY_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_CHROMEOS_POLICY_H_
 
 #include "update_engine/policy_manager/policy.h"
 
@@ -26,4 +26,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_CHROMEOS_POLICY_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_CHROMEOS_POLICY_H_
diff --git a/policy_manager/default_policy.h b/policy_manager/default_policy.h
index f5fe89d..63b674e 100644
--- a/policy_manager/default_policy.h
+++ b/policy_manager/default_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_DEFAULT_POLICY_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_DEFAULT_POLICY_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_DEFAULT_POLICY_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_DEFAULT_POLICY_H_
 
 #include "update_engine/policy_manager/policy.h"
 
@@ -31,4 +31,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_DEFAULT_POLICY_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_DEFAULT_POLICY_H_
diff --git a/policy_manager/evaluation_context-inl.h b/policy_manager/evaluation_context-inl.h
index 1413059..4e1922b 100644
--- a/policy_manager/evaluation_context-inl.h
+++ b/policy_manager/evaluation_context-inl.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_EVALUATION_CONTEXT_INL_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_INL_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_INL_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_INL_H_
 
 #include <base/logging.h>
 
@@ -39,4 +39,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_INL_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_INL_H_
diff --git a/policy_manager/evaluation_context.h b/policy_manager/evaluation_context.h
index ebbaa0f..27998d6 100644
--- a/policy_manager/evaluation_context.h
+++ b/policy_manager/evaluation_context.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_EVALUATION_CONTEXT_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_H_
 
 #include <map>
 
@@ -48,4 +48,4 @@
 // Include the implementation of the template methods.
 #include "update_engine/policy_manager/evaluation_context-inl.h"
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_EVALUATION_CONTEXT_H_
diff --git a/policy_manager/fake_random_provider.h b/policy_manager/fake_random_provider.h
index 10bd4d6..8d98689 100644
--- a/policy_manager/fake_random_provider.h
+++ b/policy_manager/fake_random_provider.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_FAKE_RANDOM_PROVIDER_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_RANDOM_PROVIDER_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_RANDOM_PROVIDER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_RANDOM_PROVIDER_H_
 
 #include "update_engine/policy_manager/fake_variable.h"
 #include "update_engine/policy_manager/random_provider.h"
@@ -27,4 +27,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_RANDOM_PROVIDER_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_RANDOM_PROVIDER_H_
diff --git a/policy_manager/fake_shill_provider.h b/policy_manager/fake_shill_provider.h
index b05a147..acc14f3 100644
--- a/policy_manager/fake_shill_provider.h
+++ b/policy_manager/fake_shill_provider.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_FAKE_SHILL_PROVIDER_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_SHILL_PROVIDER_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_SHILL_PROVIDER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_SHILL_PROVIDER_H_
 
 #include "update_engine/policy_manager/fake_variable.h"
 #include "update_engine/policy_manager/shill_provider.h"
@@ -32,4 +32,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_SHILL_PROVIDER_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_SHILL_PROVIDER_H_
diff --git a/policy_manager/fake_state.h b/policy_manager/fake_state.h
index 4d97a37..159b96b 100644
--- a/policy_manager/fake_state.h
+++ b/policy_manager/fake_state.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_FAKE_STATE_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_STATE_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_STATE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_STATE_H_
 
 #include "update_engine/policy_manager/state.h"
 
@@ -22,4 +22,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_STATE_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_STATE_H_
diff --git a/policy_manager/fake_variable.h b/policy_manager/fake_variable.h
index 541d1ec..bd113a3 100644
--- a/policy_manager/fake_variable.h
+++ b/policy_manager/fake_variable.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_FAKE_VARIABLE_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_VARIABLE_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_VARIABLE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_VARIABLE_H_
 
 #include <base/memory/scoped_ptr.h>
 
@@ -48,4 +48,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_VARIABLE_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_FAKE_VARIABLE_H_
diff --git a/policy_manager/generic_variables.h b/policy_manager/generic_variables.h
index 48764f1..f874b3b 100644
--- a/policy_manager/generic_variables.h
+++ b/policy_manager/generic_variables.h
@@ -6,8 +6,8 @@
 // used by any state provider to implement simple variables to avoid repeat the
 // same common code on different state providers.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_GENERIC_VARIABLES_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_GENERIC_VARIABLES_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_GENERIC_VARIABLES_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_GENERIC_VARIABLES_H_
 
 #include "update_engine/policy_manager/variable.h"
 
@@ -61,4 +61,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_GENERIC_VARIABLES_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_GENERIC_VARIABLES_H_
diff --git a/policy_manager/mock_policy.h b/policy_manager/mock_policy.h
index 8fcb9bc..e46b5bf 100644
--- a/policy_manager/mock_policy.h
+++ b/policy_manager/mock_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_MOCK_POLICY_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_MOCK_POLICY_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_MOCK_POLICY_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_MOCK_POLICY_H_
 
 #include <gmock/gmock.h>
 
@@ -28,4 +28,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_MOCK_POLICY_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_MOCK_POLICY_H_
diff --git a/policy_manager/pmtest_utils.h b/policy_manager/pmtest_utils.h
index 6adfec4..ade85d8 100644
--- a/policy_manager/pmtest_utils.h
+++ b/policy_manager/pmtest_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_POLICY_MANAGER_PMTEST_UTILS_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PMTEST_UTILS_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PMTEST_UTILS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PMTEST_UTILS_H_
 
 // Convenience macros for checking null-ness of pointers.
 //
@@ -20,4 +20,4 @@
 #define PMTEST_EXPECT_NULL(p) EXPECT_EQ(NULL, p)
 #define PMTEST_EXPECT_NOT_NULL(p) EXPECT_NE(reinterpret_cast<void*>(NULL), p)
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PMTEST_UTILS_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PMTEST_UTILS_H_
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_
diff --git a/policy_manager/policy_manager-inl.h b/policy_manager/policy_manager-inl.h
index 6c361a4..4317e77 100644
--- a/policy_manager/policy_manager-inl.h
+++ b/policy_manager/policy_manager-inl.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_MANAGER_INL_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_INL_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_INL_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_INL_H_
 
 #include <base/bind.h>
 
@@ -82,4 +82,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_INL_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_INL_H_
diff --git a/policy_manager/policy_manager.h b/policy_manager/policy_manager.h
index 291ff32..51cc24a 100644
--- a/policy_manager/policy_manager.h
+++ b/policy_manager/policy_manager.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_MANAGER_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_H_
 
 #include <glib.h>
 
@@ -117,4 +117,4 @@
 // Include the implementation of the template methods.
 #include "update_engine/policy_manager/policy_manager-inl.h"
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_POLICY_MANAGER_H_
diff --git a/policy_manager/provider.h b/policy_manager/provider.h
index 170c4c4..9ee5e8a 100644
--- a/policy_manager/provider.h
+++ b/policy_manager/provider.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_PROVIDER_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PROVIDER_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PROVIDER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PROVIDER_H_
 
 namespace chromeos_policy_manager {
 
@@ -32,4 +32,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PROVIDER_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_PROVIDER_H_
diff --git a/policy_manager/random_provider.h b/policy_manager/random_provider.h
index f921073..b184cf5 100644
--- a/policy_manager/random_provider.h
+++ b/policy_manager/random_provider.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_RANDOM_PROVIDER_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_RANDOM_PROVIDER_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_RANDOM_PROVIDER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_RANDOM_PROVIDER_H_
 
 #include <base/memory/scoped_ptr.h>
 
@@ -37,4 +37,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_RANDOM_PROVIDER_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_RANDOM_PROVIDER_H_
diff --git a/policy_manager/real_random_provider.h b/policy_manager/real_random_provider.h
index 4ef59a3..75c8f6e 100644
--- a/policy_manager/real_random_provider.h
+++ b/policy_manager/real_random_provider.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_REAL_RANDOM_PROVIDER_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_RANDOM_PROVIDER_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_RANDOM_PROVIDER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_RANDOM_PROVIDER_H_
 
 #include "update_engine/policy_manager/random_provider.h"
 
@@ -24,4 +24,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_RANDOM_PROVIDER_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_RANDOM_PROVIDER_H_
diff --git a/policy_manager/real_shill_provider.h b/policy_manager/real_shill_provider.h
index 26de44f..80b4802 100644
--- a/policy_manager/real_shill_provider.h
+++ b/policy_manager/real_shill_provider.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_REAL_SHILL_PROVIDER_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_SHILL_PROVIDER_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_SHILL_PROVIDER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_SHILL_PROVIDER_H_
 
 // TODO(garnold) Much of the functionality in this module was adapted from the
 // update engine's connection_manager.  We need to make sure to deprecate use of
@@ -129,4 +129,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_SHILL_PROVIDER_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_SHILL_PROVIDER_H_
diff --git a/policy_manager/real_state.h b/policy_manager/real_state.h
index 808a692..48ab56c 100644
--- a/policy_manager/real_state.h
+++ b/policy_manager/real_state.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_REAL_STATE_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_STATE_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_STATE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_STATE_H_
 
 #include "update_engine/clock_interface.h"
 #include "update_engine/dbus_wrapper_interface.h"
@@ -24,4 +24,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_STATE_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_REAL_STATE_H_
diff --git a/policy_manager/shill_provider.h b/policy_manager/shill_provider.h
index 4423f78..3530916 100644
--- a/policy_manager/shill_provider.h
+++ b/policy_manager/shill_provider.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_SHILL_PROVIDER_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_SHILL_PROVIDER_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_SHILL_PROVIDER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_SHILL_PROVIDER_H_
 
 #include <base/memory/scoped_ptr.h>
 #include <base/time.h>
@@ -67,4 +67,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_SHILL_PROVIDER_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_SHILL_PROVIDER_H_
diff --git a/policy_manager/state.h b/policy_manager/state.h
index 412925d..4950b56 100644
--- a/policy_manager/state.h
+++ b/policy_manager/state.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_STATE_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_STATE_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_STATE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_STATE_H_
 
 #include "update_engine/policy_manager/random_provider.h"
 #include "update_engine/policy_manager/shill_provider.h"
@@ -45,4 +45,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_STATE_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_STATE_H_
diff --git a/policy_manager/variable.h b/policy_manager/variable.h
index 822ab3b..2c6a8e3 100644
--- a/policy_manager/variable.h
+++ b/policy_manager/variable.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_VARIABLE_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_VARIABLE_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_VARIABLE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_VARIABLE_H_
 
 #include <algorithm>
 #include <list>
@@ -165,4 +165,4 @@
 
 }  // namespace chromeos_policy_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_VARIABLE_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POLICY_MANAGER_VARIABLE_H_