diff --git a/timedesc/RFC9110_parsers.ml b/timedesc/RFC9110_parsers.ml
index c20a4f7f..9b7ae34b 100644
--- a/timedesc/RFC9110_parsers.ml
+++ b/timedesc/RFC9110_parsers.ml
@@ -20,7 +20,7 @@ let month_p : int Angstrom.t =
   if String.length s < 3 then
     fail (Printf.sprintf "Invalid month: %s" s)
   else (
-    (match String.lowercase_ascii @@ StringLabels.sub ~pos:0 ~len:3 s with
+    (match String.lowercase_ascii @@ String.sub s 0 3 with
      | "jan" -> return 1
      | "feb" -> return 2
      | "mar" -> return 3
diff --git a/timedesc/timedesc.mli b/timedesc/timedesc.mli
index 41152763..8e122787 100644
--- a/timedesc/timedesc.mli
+++ b/timedesc/timedesc.mli
@@ -2192,7 +2192,7 @@ module Utils : sig
 
       You are advised to read the source code of the following functions in [date_time_utils.ml] if you intend to use them
                                                                                to ensure they behave as you expect.
-                                                                            *)
+  *)
 
   val is_leap_year : year:int -> bool