diff --git a/src/types.ml b/src/types.ml
index 6c401bda..ac07fe92 100644
--- a/src/types.ml
+++ b/src/types.ml
@@ -30,6 +30,10 @@ module Config_types = struct
   end
 end
 
+module HashCode = struct
+  type t = string
+end
+
 (* https://docs.taler.net/core/api-common.html#tsref-type-ErrorDetail *)
 module ErrorDetail = struct
   (* TODO GANA error codes
@@ -162,11 +166,6 @@ end = struct
   let jsont = Jsont.of_of_string ~kind:"RsaSignature" of_b32 ~enc:to_b32
 end
 
-module HashCode = struct
-  (* 32-byte value representing a point on Curve25519. *)
-  type cs25519Point = string
-end
-
 module RsaDenominationKey = struct
   type t = {
     age_mask: int;