diff --git a/format-code.sh b/format-code.sh
new file mode 100755
index 0000000..a824ad1
--- /dev/null
+++ b/format-code.sh
@@ -0,0 +1,34 @@
+#!/bin/sh
+
+set -euo
+
+set -x
+
+[ -f .clang-format ] && rm .clang-format
+
+CLANG_FORMAT="$(which clang-format-5.0)"
+
+# phosphor-mboxd is a fork of mboxbridge, the reference mbox daemon
+# implementation. mboxbridge is C written with the style of the Linux kernel.
+#
+# phosphor-mboxd extended the reference in C++, and used the OpenBMC C++ style.
+#
+# To remain compliant with the C++ style guide *and* preserve source
+# compatibility with the upstream reference implementation, use two separate
+# styles.
+#
+# Further, clang-format supports describing styles for multiple languages in
+# the one .clang-format file, but *doesn't* make a distinction between C and
+# C++. So we need two files. It gets worse: the -style parameter doesn't take
+# the path to a configuration file as an argument, you instead specify the
+# literal 'file' and it goes looking for a .clang-format or _clang-format file. 
+# So now we need to symlink different files in place before calling
+# ${CLANG_FORMAT}. Everything is terrible.
+#
+# ln -sf .clang-format-c .clang-format
+# git ls-files | grep '\.[ch]$' | xargs "${CLANG_FORMAT}" -i -style=file
+
+ln -sf .clang-format-c++ .clang-format
+git ls-files | grep '\.[ch]pp$' | xargs "${CLANG_FORMAT}" -i -style=file
+
+rm .clang-format