diff --git a/error.h b/error.h
index f76062c..65fb3e3 100644
--- a/error.h
+++ b/error.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 SHILL_ERROR_
-#define SHILL_ERROR_
+#ifndef SHILL_ERROR_H_
+#define SHILL_ERROR_H_
 
 #include <string>
 
@@ -97,4 +97,4 @@
 // stream operator provided to facilitate logging
 std::ostream &operator<<(std::ostream &stream, const shill::Error &error);
 
-#endif  // SHILL_ERROR_
+#endif  // SHILL_ERROR_H_