diff --git a/libcurl_http_fetcher.h b/libcurl_http_fetcher.h
index 35de32a..ff0275a 100644
--- a/libcurl_http_fetcher.h
+++ b/libcurl_http_fetcher.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_LIBCURL_HTTP_FETCHER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H_
 
 #include <map>
 #include <string>
@@ -304,4 +304,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H_