diff --git a/ocaml/To_md5.ml b/ocaml/To_md5.ml
new file mode 100644
index 00000000..33015d75
--- /dev/null
+++ b/ocaml/To_md5.ml
@@ -0,0 +1,11 @@
+open Core.Std;;
+open Qptypes;;
+
+let to_md5 sexp_of_t t =
+  sexp_of_t t
+  |> Sexp.to_string
+  |> Cryptokit.hash_string (Cryptokit.Hash.md5 ())
+  |> Cryptokit.transform_string (Cryptokit.Hexa.encode ())
+  |> MD5.of_string
+;;
+