diff --git a/src/hash.ml b/src/hash.ml
index 317ae2b1..36be50ee 100644
--- a/src/hash.ml
+++ b/src/hash.ml
@@ -1,10 +1,8 @@
-(* TODO hash:
+(* TODO
    json:
      "A JSON object is canonicalized by converting it to an ASCII byte array
       with the algorithm specified in RFC 8785. The resulting bytes are
       terminated with a single 0-byte and then hashed with SHA512." *)
-(* C-terminated strings
-   some strings need to be hashed with a '\0' termination char *)
 
 open Digestif
 
@@ -38,7 +36,7 @@ module H32 = struct
     map (bytes 32) of_octets to_octets
 
   (* hashes are not b32 encoded in the database *)
-  let caqti : t Caqti_type.t =
+  let caqti =
     let open Caqti_type in
     custom
       ~encode:(fun v -> Ok (to_octets v))
@@ -73,7 +71,7 @@ module H64 = struct
     map (bytes 64) of_octets to_octets
 
   (* hashes are not b32 encoded in the database *)
-  let caqti : t Caqti_type.t =
+  let caqti =
     let open Caqti_type in
     custom
       ~encode:(fun v -> Ok (to_octets v))
@@ -85,7 +83,8 @@ module H64 = struct
     Jsont.of_of_string ~kind:"Hash 64" of_b32 ~enc
 end
 
-(* Hash over string + '\0' *)
+(* C-terminated strings
+   some strings need to be hashed with a '\0' termination char *)
 module Cstring = struct
   module H32 = struct
     include H32