diff --git a/presubmit.sh b/presubmit.sh
new file mode 100755
index 0000000..735b6b3
--- /dev/null
+++ b/presubmit.sh
@@ -0,0 +1,9 @@
+#!/bin/sh
+# Copyright 2017 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.
+
+find \
+	'(' -name '*.[ch]' -or -name '*.cc' ')' \
+	-not -name 'gbm.h' \
+	-exec clang-format -style=file -i {} +