+--- ocaml-data-notation-0.0.11/setup.ml.orig 2013-11-22 01:34:28.000000000 +0100
++++ ocaml-data-notation-0.0.11/setup.ml 2021-09-18 20:33:00.818590112 +0200
+@@ -227,11 +227,9 @@ module OASISString = struct
+ raise Not_found
+
+ let replace_chars f s =
+- let buf = String.make (String.length s) 'X' in
+- for i = 0 to String.length s - 1 do
+- buf.[i] <- f s.[i]
+- done;
+- buf
++ let buf = Buffer.create (String.length s) in
++ String.iter (fun c -> Buffer.add_char buf (f c)) s;
++ Buffer.contents buf
+
+ end
+