diff --git a/vendors/ocaml-hacl/src/hacl.ml b/vendors/ocaml-hacl/src/hacl.ml
index 849eb849d..22a7a557d 100644
--- a/vendors/ocaml-hacl/src/hacl.ml
+++ b/vendors/ocaml-hacl/src/hacl.ml
@@ -50,6 +50,10 @@ module Hash = struct
       mutable pos : int ;
     }
 
+    let bytes = S.bytes
+    let blockbytes = S.blockbytes
+    let statebytes = S.statebytes
+
     let init () =
       let state = Bigstring.create S.statebytes in
       let buf = Bigstring.create S.blockbytes in
diff --git a/vendors/ocaml-hacl/src/hacl.mli b/vendors/ocaml-hacl/src/hacl.mli
index 151585d8e..ca9fba02b 100644
--- a/vendors/ocaml-hacl/src/hacl.mli
+++ b/vendors/ocaml-hacl/src/hacl.mli
@@ -31,6 +31,10 @@ module Hash : sig
   module SHA256 : sig
     type state
 
+    val bytes : int
+    val blockbytes : int
+    val statebytes : int
+
     (** Incremental Interface *)
 
     val init : unit -> state
@@ -54,6 +58,10 @@ module Hash : sig
   module SHA512 : sig
     type state
 
+    val bytes : int
+    val blockbytes : int
+    val statebytes : int
+
     (** Incremental Interface *)
 
     val init : unit -> state