diff --git a/certificate_checker.cc b/certificate_checker.cc
index 579038e..1f19baf 100644
--- a/certificate_checker.cc
+++ b/certificate_checker.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -8,6 +8,7 @@
 
 #include <base/string_number_conversions.h>
 #include <base/string_util.h>
+#include <base/stringprintf.h>
 #include <base/logging.h>
 #include <curl/curl.h>
 #include <metrics/metrics_library.h>