diff --git a/tools/ocaml/Makefile b/tools/ocaml/Makefile
index a7c04b6546..85bfd087c9 100644
--- a/tools/ocaml/Makefile
+++ b/tools/ocaml/Makefile
@@ -34,3 +34,7 @@ build-tools-oxenstored:
 	$(MAKE) -s -C libs/xb
 	$(MAKE) -s -C libs/xc
 	$(MAKE) -C xenstored
+
+.PHONY: format
+format:
+	git ls-files '*.ml' '*.mli' | xargs -n1 ocp-indent -i