diff --git a/manifest/main.ml b/manifest/main.ml
index e68fe43879aef55ad439991798a34cde8e66dcb9..c9b46ae90a9ffc40181c011c016bad6478b34be3 100644
--- a/manifest/main.ml
+++ b/manifest/main.ml
@@ -1152,6 +1152,7 @@ let octez_webassembly_interpreter =
     ~synopsis:"WebAssembly reference interpreter with tweaks for Tezos"
     ~dune:Dune.[[S "include_subdirs"; S "unqualified"]]
     ~deps:[octez_lwt_result_stdlib; zarith; lazy_containers |> open_]
+    ~preprocess:[pps ppx_deriving_show]
 
 let _octez_webassembly_repl =
   private_exe
diff --git a/opam/tezos-webassembly-interpreter.opam b/opam/tezos-webassembly-interpreter.opam
index dab8fbe57fe8202f26d9f630ef73b4be345c0548..35e7d63d52ec6f8636bad9ca421c6bbbe2989d8b 100644
--- a/opam/tezos-webassembly-interpreter.opam
+++ b/opam/tezos-webassembly-interpreter.opam
@@ -9,6 +9,7 @@ dev-repo: "git+https://gitlab.com/tezos/tezos.git"
 license: "Apache-2.0"
 depends: [
   "dune" { >= "3.0" }
+  "ppx_deriving"
   "tezos-lwt-result-stdlib"
   "zarith" { >= "1.12" & < "1.13" }
   "lazy-containers"
diff --git a/src/lib_scoru_wasm/test/ast_printer.ml b/src/lib_scoru_wasm/test/ast_printer.ml
index 44fa6a3778c18df1d74234fea51fa2ec885921a0..aed91327a2f16dddda42088e68c044d4f1df5aef 100644
--- a/src/lib_scoru_wasm/test/ast_printer.ml
+++ b/src/lib_scoru_wasm/test/ast_printer.ml
@@ -26,59 +26,17 @@
 open Lazy_containers
 open Tezos_webassembly_interpreter
 
-let pp_pos out {Source.file; line; column} =
-  Format.fprintf
-    out
-    "@[<hv 2>{file = %S;@; line = %d;@; column = %d}@]"
-    (String.escaped file)
-    line
-    column
-
-let pp_region out {Source.left; right} =
-  Format.fprintf
-    out
-    "@[<hv 2>{left = %a;@; right = %a}@]"
-    pp_pos
-    left
-    pp_pos
-    right
-
-let pp_phrase pp_it out Source.{it; at} =
-  Format.fprintf out "@[<hv 2>{it = %a;@; at = %a}@]" pp_it it pp_region at
-
 let pp_int32 out n = Format.fprintf out "%ld" n
 
 let pp_int64 out n = Format.fprintf out "%Ld" n
 
-let pp_var = pp_phrase pp_int32
+let pp_f32 _out _f32 =
+  Stdlib.failwith "32bit floating point values are not supported"
 
-let pp_num_type out num =
-  Format.fprintf
-    out
-    "%s"
-    (match num with
-    | Types.I32Type -> "I32Type"
-    | I64Type -> "I64Type"
-    | F32Type -> "F32Type"
-    | F64Type -> "F64Type")
-
-let pp_ref_type out ref =
-  Format.fprintf
-    out
-    "%s"
-    (match ref with
-    | Types.FuncRefType -> "FuncRefType"
-    | ExternRefType -> "ExternRefType")
-
-let pp_vec_type out = function
-  | Types.V128Type -> Format.pp_print_string out "V128Type"
+let pp_f64 _out _f64 =
+  Stdlib.failwith "64bit floating point values are not supported"
 
-let pp_value_type out vt =
-  let open Types in
-  match vt with
-  | NumType nt -> Format.fprintf out "NumType%a" pp_num_type nt
-  | VecType vt -> Format.fprintf out "VecType %a" pp_vec_type vt
-  | RefType rt -> Format.fprintf out "RefType %a" pp_ref_type rt
+let pp_var = Source.pp_phrase pp_int32
 
 let pp_list pp out x =
   Format.fprintf
@@ -87,13 +45,7 @@ let pp_list pp out x =
     (Format.pp_print_list ~pp_sep:(fun out () -> Format.fprintf out ";@;") pp)
     x
 
-let pp_value_type_list = pp_list pp_value_type
-
-let pp_block_label out (Ast.Block_label l) =
-  Format.fprintf out "Block_label @[<hv 2>(%ld)@]" l
-
-let pp_data_label out (Ast.Data_label l) =
-  Format.fprintf out "Data_label @[<hv 2>(%ld)@]" l
+let pp_value_type_list = pp_list Types.pp_value_type
 
 let pp_opt pp out = function
   | Some x -> Format.fprintf out "Some @[<hv 2>(%a)@]" pp x
@@ -103,10 +55,6 @@ let pp_unit out () = Format.pp_print_string out "()"
 
 let pp_pair pp1 pp2 out (x, y) = Format.fprintf out "(%a, %a)" pp1 x pp2 y
 
-let pp_block_type out = function
-  | Ast.VarBlockType v -> pp_var out v
-  | Ast.ValBlockType v -> pp_opt pp_value_type out v
-
 let pp_memop pp_ty pp_pack out {Ast.ty; align; pack; offset} =
   Format.fprintf
     out
@@ -119,145 +67,7 @@ let pp_memop pp_ty pp_pack out {Ast.ty; align; pack; offset} =
     pp_int32
     offset
 
-let pp_pack_size out ps =
-  Format.fprintf
-    out
-    "%s"
-    (match ps with
-    | Types.Pack8 -> "Pack8"
-    | Pack16 -> "Pack16"
-    | Pack32 -> "Pack32"
-    | Pack64 -> "Pack64")
-
-let pp_extension out ex =
-  Format.fprintf out "%s" (match ex with Types.SX -> "SX" | ZX -> "ZX")
-
-let pp_load_op =
-  pp_memop pp_num_type (pp_opt (pp_pair pp_pack_size pp_extension))
-
-let pp_store_op = pp_memop pp_num_type (pp_opt pp_pack_size)
-
-let pp_pack_shape out p =
-  Format.fprintf
-    out
-    "%s"
-    (match p with
-    | Types.Pack8x8 -> "Pack8x8"
-    | Pack16x4 -> "Pack16x4"
-    | Pack32x2 -> "Pack32x2")
-
-let pp_vec_extension out = function
-  | Types.ExtLane (ps, e) -> (pp_pair pp_pack_shape pp_extension) out (ps, e)
-  | ExtSplat -> Format.pp_print_string out "ExtSplat"
-  | ExtZero -> Format.pp_print_string out "ExZero"
-
-let pp_vec_load_op =
-  pp_memop pp_vec_type (pp_opt @@ pp_pair pp_pack_size pp_vec_extension)
-
-let pp_vec_store_op = pp_memop pp_vec_type pp_unit
-
-let pp_vec_laneop =
-  pp_pair (pp_memop pp_vec_type pp_pack_size) Format.pp_print_int
-
-let pp_value_op pp_int32 pp_int64 out = function
-  | Values.I32 x -> pp_int32 out x
-  | I64 x -> pp_int64 out x
-  | _ -> Stdlib.failwith "Floating point values are not supported"
-
-let pp_num = pp_phrase (pp_value_op pp_int32 pp_int64)
-
-let pp_laneop pp_i8x16 pp_i16x8 pp_i32x4 pp_i64x2 out = function
-  | V128.I8x16 x -> pp_i8x16 x out
-  | V128.I16x8 x -> pp_i16x8 x out
-  | V128.I32x4 x -> pp_i32x4 x out
-  | V128.I64x2 x -> pp_i64x2 x out
-  | _ -> Stdlib.failwith "Floating point ops are not supported"
-
-let pp_int_relop out op =
-  Format.pp_print_string
-    out
-    (match op with
-    | Ast.IntOp.Eq -> "Eq"
-    | Ne -> "Ne"
-    | LtS -> "LtS"
-    | LtU -> "LtU"
-    | LeS -> "LeS"
-    | LeU -> "LeU"
-    | GtS -> "GtS"
-    | GtU -> "GtU"
-    | GeS -> "GeS"
-    | GeU -> "GeU")
-
-let float_relop_gen out op =
-  Format.pp_print_string
-    out
-    (match op with
-    | Ast.FloatOp.Eq -> "Eq"
-    | Ne -> "Ne"
-    | Lt -> "Lt"
-    | Le -> "Le"
-    | Gt -> "Gt"
-    | Ge -> "Ge")
-
-let pp_relop = pp_value_op pp_int_relop pp_int_relop
-
-let pp_int_unop out op =
-  match op with
-  | Ast.IntOp.Clz -> Format.pp_print_string out "Clz"
-  | Ctz -> Format.pp_print_string out "Ctz"
-  | Popcnt -> Format.pp_print_string out "Popcnt"
-  | ExtendS ps -> Format.fprintf out "Extend %a" pp_pack_size ps
-
-let pp_int_binop out op =
-  Format.pp_print_string
-    out
-    (match op with
-    | Ast.IntOp.Add -> "Add"
-    | Sub -> "Sub"
-    | Mul -> "Mul"
-    | DivS -> "DivS"
-    | DivU -> "DivU"
-    | RemS -> "RemS"
-    | RemU -> "RemU"
-    | And -> "And"
-    | Or -> "Or"
-    | Xor -> "Xor"
-    | Shl -> "Shl"
-    | ShrS -> "ShrS"
-    | ShrU -> "ShrU"
-    | Rotl -> "Rotl"
-    | Rotr -> "Rotr")
-
-let pp_int_cvtop out op =
-  Format.pp_print_string
-    out
-    (match op with
-    | Ast.IntOp.ExtendSI32 -> "ExtendSI32"
-    | ExtendUI32 -> "ExtendUI32"
-    | WrapI64 -> "WrapI64"
-    | TruncSF32 -> "TruncSF32"
-    | TruncUF32 -> "TruncUF32"
-    | TruncSF64 -> "TruncSF64"
-    | TruncUF64 -> "TruncUF64"
-    | TruncSatSF32 -> "TruncSatSF32"
-    | TruncSatUF32 -> "TruncSatUF32"
-    | TruncSatSF64 -> "TruncSatSF64"
-    | TruncSatUF64 -> "TruncSatUF64"
-    | ReinterpretFloat -> "ReinterpretFloat")
-
-let pp_cvtop = pp_value_op pp_int_cvtop pp_int_cvtop
-
-let pp_unop = pp_value_op pp_int_unop pp_int_unop
-
-let pp_binop = pp_value_op pp_int_binop pp_int_binop
-
-let pp_vec =
-  let pp out = function
-    | Values.V128 bits ->
-        let hash = Hashtbl.hash bits in
-        Format.fprintf out "V128 (#%d)" hash
-  in
-  pp_phrase pp
+let pp_num = Source.pp_phrase (Values.pp_op pp_int32 pp_int64 pp_f32 pp_f64)
 
 (*
   Generate instructions. The following are missing:
@@ -326,13 +136,13 @@ let pp_instr' out instr =
       Format.fprintf out "BrTable(%a, %a)" (pp_list pp_var) vs pp_var v
   | CallIndirect (v1, v2) ->
       Format.fprintf out "CallIndirect(%a, %a)" pp_var v1 pp_var v2
-  | Load o -> Format.fprintf out "Load(%a)" pp_load_op o
-  | Store o -> Format.fprintf out "Store(%a)" pp_store_op o
-  | VecLoad o -> Format.fprintf out "VecLoad(%a)" pp_vec_load_op o
-  | VecStore o -> Format.fprintf out "VecSore(%a)" pp_vec_store_op o
+  | Load o -> Format.fprintf out "Load(%a)" pp_loadop o
+  | Store o -> Format.fprintf out "Store(%a)" pp_storeop o
+  | VecLoad o -> Format.fprintf out "VecLoad(%a)" pp_vec_loadop o
+  | VecStore o -> Format.fprintf out "VecSore(%a)" pp_vec_storeop o
   | VecLoadLane o -> Format.fprintf out "VecLoadLane(%a)" pp_vec_laneop o
   | VecStoreLane o -> Format.fprintf out "VecSoreLane(%a)" pp_vec_laneop o
-  | RefNull rt -> Format.fprintf out "RefNull (%a)" pp_ref_type rt
+  | RefNull rt -> Format.fprintf out "RefNull (%a)" Types.pp_ref_type rt
   | Const c -> Format.fprintf out "Const(%a)" pp_num c
   | Compare c -> Format.fprintf out "Compare(%a)" pp_relop c
   | Unary c -> Format.fprintf out "Unary (%a)" pp_unop c
@@ -341,7 +151,7 @@ let pp_instr' out instr =
   | VecConst c -> Format.fprintf out "VecConst (%a)" pp_vec c
   | _ -> Stdlib.failwith "Unsupported instruction"
 
-let pp_instr = pp_phrase pp_instr'
+let pp_instr = Source.pp_phrase pp_instr'
 
 let pp_vector pp out v =
   (* Force evaluation of the vector. *)
@@ -353,22 +163,22 @@ let pp_vector_z pp out v =
   let _ = Lwt_main.run @@ Lazy_vector.ZVector.to_list v in
   Lazy_vector.ZVector.pp pp out v
 
-let pp_resul_type = pp_vector pp_value_type
+let pp_resul_type = pp_vector Types.pp_value_type
 
 let pp_func_type out = function
   | Types.FuncType (pt, rt) ->
       Format.fprintf out "FuncType (%a, %a)" pp_resul_type pt pp_resul_type rt
 
 let pp_func =
-  pp_phrase @@ fun out {Ast.ftype; locals; body} ->
+  Source.pp_phrase @@ fun out {Ast.ftype; locals; body} ->
   Format.fprintf
     out
     "@[<hv 2>{ftype = %a;@; locals = %a;@; body = %a}@]"
     pp_var
     ftype
-    (pp_vector pp_value_type)
+    (pp_vector Types.pp_value_type)
     locals
-    pp_block_label
+    Ast.pp_block_label
     body
 
 let pp_func out func =
@@ -384,30 +194,11 @@ let pp_func out func =
   | Func.HostFunc (ft, n) ->
       Format.fprintf out "HostFunc @[<hv 2>(%a,@; %s)@]" pp_func_type ft n
 
-let pp_ref_type out = function
-  | Types.FuncRefType -> Format.fprintf out "FuncRefType"
-  | Types.ExternRefType -> Format.fprintf out "ExternRefType"
-
-let pp_limit pp out {Types.min; Types.max} =
-  Format.fprintf out "{min = %a; max = %a}" pp min (pp_opt pp) max
-
-let pp_table_type out (Types.TableType (limit, ref_type)) =
-  Format.fprintf
-    out
-    "Types.TableType (%a, %a)"
-    (pp_limit pp_int32)
-    limit
-    pp_ref_type
-    ref_type
-
 let pp_ref out = function
-  | Values.NullRef rt -> Format.fprintf out "NullRef (%a)" pp_ref_type rt
+  | Values.NullRef rt -> Format.fprintf out "NullRef (%a)" Types.pp_ref_type rt
   | Values.ExternRef n -> Format.fprintf out "ExternRef(%a)" pp_int32 n
   | _ -> Stdlib.failwith "Unsupported value ref"
 
-let pp_memory_type out (Types.MemoryType limit) =
-  Format.fprintf out "MemoryType %a" (pp_limit pp_int32) limit
-
 let pp_chunk_byte_vector out chunks =
   let bs = Lwt_main.run @@ Chunked_byte_vector.to_string chunks in
   (* We just show the hash of the chunk in order to avoid too much noise. *)
@@ -420,25 +211,12 @@ let pp_table out t =
   Format.fprintf
     out
     "@[<hv 2>{ty = %a;@; content = (%a)}@]"
-    pp_table_type
+    Types.pp_table_type
     ty
     (pp_vector pp_ref)
     c
 
-let pp_mutable out = function
-  | Types.Immutable -> Format.pp_print_string out "Immutable"
-  | Types.Mutable -> Format.pp_print_string out "Mutable"
-
-let pp_global_type out (Types.GlobalType (vt, mt)) =
-  Format.fprintf
-    out
-    "GlobalType @[<hv 2>(%a, %a)@]"
-    pp_value_type
-    vt
-    pp_mutable
-    mt
-
-let pp_value_num = pp_value_op pp_int32 pp_int64
+let pp_value_num = Values.pp_op pp_int32 pp_int64 pp_f32 pp_f64
 
 let pp_value out = function
   | Values.Num n -> Format.fprintf out "Num %a" pp_value_num n
@@ -453,7 +231,7 @@ let pp_memory out memory =
   Format.fprintf
     out
     "@[<hv 2>{ty = %a;@; content = %a}@]"
-    pp_memory_type
+    Types.pp_memory_type
     ty
     pp_chunk_byte_vector
     content
@@ -464,7 +242,7 @@ let pp_global out global =
   Format.fprintf
     out
     "@[<hv 2>{ty = %a;@; content = %a}@]"
-    pp_global_type
+    Types.pp_global_type
     ty
     pp_value
     content
@@ -494,7 +272,7 @@ let pp_allocations out allocations =
     pp_datas_table
     allocations.Ast.datas
 
-let pp_data_inst out ref = pp_data_label out !ref
+let pp_data_inst out ref = Ast.pp_data_label out !ref
 
 let pp_module out
     {
@@ -556,7 +334,7 @@ let rec pp_admin_instr' out instr =
       Format.fprintf
         out
         "From_block @[<hv 2>(%a,@; %li)@]"
-        pp_block_label
+        Ast.pp_block_label
         block
         index
   | Plain instr -> Format.fprintf out "Plain @[<hv 2>%a@]" pp_instr' instr
@@ -602,27 +380,12 @@ let rec pp_admin_instr' out instr =
 
 and pp_admin_instr out instr = pp_admin_instr' out instr.Source.it
 
-let pp_input_message out message =
-  let open Input_buffer in
-  Format.fprintf
-    out
-    "@[<v 2>{rtype = %li;@;\
-     raw_level = %li;@;\
-     message_counter = %s;@;\
-     payload = %a;@;\
-     }@]"
-    message.rtype
-    message.raw_level
-    (Z.to_string message.message_counter)
-    Hex.pp
-    (Hex.of_bytes message.payload)
-
 let pp_input_buffer out input =
   let open Input_buffer in
   Format.fprintf
     out
     "@[<v 2>{content = %a;@;num_elements = %s;@;}@]"
-    (pp_vector_z pp_input_message)
+    (pp_vector_z Input_buffer.pp_message)
     (Lazy_vector.Mutable.ZVector.snapshot input.content)
     (Z.to_string input.num_elements)
 
diff --git a/src/lib_webassembly/dune b/src/lib_webassembly/dune
index 918b7aa412533ad524a08775759534777ec0bf76..7e822e15bcd9f947c6905c4a995196d4960a2e8b 100644
--- a/src/lib_webassembly/dune
+++ b/src/lib_webassembly/dune
@@ -9,6 +9,7 @@
   tezos-lwt-result-stdlib
   zarith
   lazy-containers)
+ (preprocess (pps ppx_deriving.show))
  (flags
   (:standard)
   -open Lazy_containers))
diff --git a/src/lib_webassembly/exec/v128.ml b/src/lib_webassembly/exec/v128.ml
index 6cd736ebd83e6f8339cb9648a646b1df82c6334f..6e6c75d7dfce2d903a82be5fff3d1e9f44f71d13 100644
--- a/src/lib_webassembly/exec/v128.ml
+++ b/src/lib_webassembly/exec/v128.ml
@@ -707,6 +707,8 @@ let of_strings shape ss =
         ss) ;
   to_string b
 
+let pp fmt v128 = Format.pp_print_string fmt v128
+
 let string_of_shape = function
   | I8x16 _ -> "i8x16"
   | I16x8 _ -> "i16x8"
diff --git a/src/lib_webassembly/exec/v128.mli b/src/lib_webassembly/exec/v128.mli
index 0dbdcf46dc16bb41b2ecfcd10ed932d8dcaad148..9dae83098de28bbba6d712c4530454341f22b069 100644
--- a/src/lib_webassembly/exec/v128.mli
+++ b/src/lib_webassembly/exec/v128.mli
@@ -38,6 +38,8 @@ val to_hex_string : t -> string
 
 val of_strings : shape -> string list -> t
 
+val pp : Format.formatter -> t -> unit
+
 (* Shape-based operations *)
 
 module type IntShape = sig
diff --git a/src/lib_webassembly/runtime/input_buffer.ml b/src/lib_webassembly/runtime/input_buffer.ml
index 3acb67621f765d31b7abcc55b5b4acd23afd98d7..39ca0715afa752776cb4d1d4e5bee293e65b094d 100644
--- a/src/lib_webassembly/runtime/input_buffer.ml
+++ b/src/lib_webassembly/runtime/input_buffer.ml
@@ -1,9 +1,10 @@
 type message = {
   rtype : int32;
   raw_level : int32;
-  message_counter : Z.t;
+  message_counter : Z.t; [@printer Z.pp_print]
   payload : bytes;
 }
+[@@deriving show]
 
 exception Bounds
 
diff --git a/src/lib_webassembly/runtime/input_buffer.mli b/src/lib_webassembly/runtime/input_buffer.mli
index 8d734257fd00e79f109758352893f217a5b32660..fa17ddefe4db1c4ae036a05464d9cba177d9b6a4 100644
--- a/src/lib_webassembly/runtime/input_buffer.mli
+++ b/src/lib_webassembly/runtime/input_buffer.mli
@@ -7,6 +7,7 @@ type message = {
   message_counter : Z.t;
   payload : bytes;
 }
+[@@deriving show]
 
 (** An element of type t will have a content which is a lazy_vector of messages
     and a pointer to the number of elements to be able to dequeue. At this point
diff --git a/src/lib_webassembly/syntax/ast.ml b/src/lib_webassembly/syntax/ast.ml
index fb16ca18a6ccffab73f7a351e9991b82cb378d47..880cbd286841a5c3638bcce0076d740c7482112d 100644
--- a/src/lib_webassembly/syntax/ast.ml
+++ b/src/lib_webassembly/syntax/ast.ml
@@ -25,7 +25,7 @@ type void = Lib.void
 (* Operators *)
 
 module IntOp = struct
-  type unop = Clz | Ctz | Popcnt | ExtendS of pack_size
+  type unop = Clz | Ctz | Popcnt | ExtendS of pack_size [@@deriving show]
 
   type binop =
     | Add
@@ -43,10 +43,12 @@ module IntOp = struct
     | ShrU
     | Rotl
     | Rotr
+  [@@deriving show]
 
   type testop = Eqz
 
   type relop = Eq | Ne | LtS | LtU | GtS | GtU | LeS | LeU | GeS | GeU
+  [@@deriving show]
 
   type cvtop =
     | ExtendSI32
@@ -61,16 +63,18 @@ module IntOp = struct
     | TruncSatSF64
     | TruncSatUF64
     | ReinterpretFloat
+  [@@deriving show]
 end
 
 module FloatOp = struct
   type unop = Neg | Abs | Ceil | Floor | Trunc | Nearest | Sqrt
+  [@@deriving show]
 
-  type binop = Add | Sub | Mul | Div | Min | Max | CopySign
+  type binop = Add | Sub | Mul | Div | Min | Max | CopySign [@@deriving show]
 
   type testop = |
 
-  type relop = Eq | Ne | Lt | Gt | Le | Ge
+  type relop = Eq | Ne | Lt | Gt | Le | Ge [@@deriving show]
 
   type cvtop =
     | ConvertSI32
@@ -80,6 +84,7 @@ module FloatOp = struct
     | PromoteF32
     | DemoteF64
     | ReinterpretInt
+  [@@deriving show]
 end
 
 module I32Op = IntOp
@@ -201,12 +206,16 @@ end
 type testop = (I32Op.testop, I64Op.testop, F32Op.testop, F64Op.testop) Values.op
 
 type unop = (I32Op.unop, I64Op.unop, F32Op.unop, F64Op.unop) Values.op
+[@@deriving show]
 
 type binop = (I32Op.binop, I64Op.binop, F32Op.binop, F64Op.binop) Values.op
+[@@deriving show]
 
 type relop = (I32Op.relop, I64Op.relop, F32Op.relop, F64Op.relop) Values.op
+[@@deriving show]
 
 type cvtop = (I32Op.cvtop, I64Op.cvtop, F32Op.cvtop, F64Op.cvtop) Values.op
+[@@deriving show]
 
 type vec_testop = V128Op.testop Values.vecop
 
@@ -237,32 +246,35 @@ type vec_extractop = V128Op.extractop Values.vecop
 type vec_replaceop = V128Op.replaceop Values.vecop
 
 type ('t, 'p) memop = {ty : 't; align : int; offset : int32; pack : 'p}
+[@@deriving show]
 
-type loadop = (num_type, (pack_size * extension) option) memop
+type loadop = (num_type, (pack_size * extension) option) memop [@@deriving show]
 
-type storeop = (num_type, pack_size option) memop
+type storeop = (num_type, pack_size option) memop [@@deriving show]
 
 type vec_loadop = (vec_type, (pack_size * vec_extension) option) memop
+[@@deriving show]
 
-type vec_storeop = (vec_type, unit) memop
+type vec_storeop = (vec_type, unit) memop [@@deriving show]
 
-type vec_laneop = (vec_type, pack_size) memop * int
+type vec_laneop = (vec_type, pack_size) memop * int [@@deriving show]
 
 (* Expressions *)
 
-type var = int32 Source.phrase
+type var = int32 Source.phrase [@@deriving show]
 
 type num = Values.num Source.phrase
 
-type vec = Values.vec Source.phrase
+type vec = Values.vec Source.phrase [@@deriving show]
 
 type name = int Vector.t
 
 type name_list = int list
 
 type block_type = VarBlockType of var | ValBlockType of value_type option
+[@@deriving show]
 
-type block_label = Block_label of int32
+type block_label = Block_label of int32 [@@deriving show]
 
 type nonrec instr' =
   | Unreachable (* trap unconditionally *)
@@ -367,7 +379,7 @@ and elem_segment' = {
   emode : segment_mode;
 }
 
-type data_label = Data_label of int32
+type data_label = Data_label of int32 [@@deriving show]
 
 type data_segment = data_segment' Source.phrase
 
diff --git a/src/lib_webassembly/syntax/types.ml b/src/lib_webassembly/syntax/types.ml
index d7a499fc0c596a7b771058829367718a635b4d67..58d9c36a839d9ec246c78f6da5e4627685bc9221 100644
--- a/src/lib_webassembly/syntax/types.ml
+++ b/src/lib_webassembly/syntax/types.ml
@@ -1,29 +1,30 @@
 (* Types *)
 
-type num_type = I32Type | I64Type | F32Type | F64Type
+type num_type = I32Type | I64Type | F32Type | F64Type [@@deriving show]
 
-type vec_type = V128Type
+type vec_type = V128Type [@@deriving show]
 
-type ref_type = FuncRefType | ExternRefType
+type ref_type = FuncRefType | ExternRefType [@@deriving show]
 
 type value_type =
   | NumType of num_type
   | VecType of vec_type
   | RefType of ref_type
+[@@deriving show]
 
 type result_type = value_type Lazy_vector.Int32Vector.t
 
 type func_type = FuncType of result_type * result_type
 
-type 'a limits = {min : 'a; max : 'a option}
+type 'a limits = {min : 'a; max : 'a option} [@@deriving show]
 
-type mutability = Immutable | Mutable
+type mutability = Immutable | Mutable [@@deriving show]
 
-type table_type = TableType of Int32.t limits * ref_type
+type table_type = TableType of Int32.t limits * ref_type [@@deriving show]
 
-type memory_type = MemoryType of Int32.t limits
+type memory_type = MemoryType of Int32.t limits [@@deriving show]
 
-type global_type = GlobalType of value_type * mutability
+type global_type = GlobalType of value_type * mutability [@@deriving show]
 
 type extern_type =
   | ExternFuncType of func_type
@@ -32,13 +33,14 @@ type extern_type =
   | ExternGlobalType of global_type
 
 (* Reference-interpreter-todo: these types should move somewhere else *)
-type pack_size = Pack8 | Pack16 | Pack32 | Pack64
+type pack_size = Pack8 | Pack16 | Pack32 | Pack64 [@@deriving show]
 
-type extension = SX | ZX
+type extension = SX | ZX [@@deriving show]
 
-type pack_shape = Pack8x8 | Pack16x4 | Pack32x2
+type pack_shape = Pack8x8 | Pack16x4 | Pack32x2 [@@deriving show]
 
 type vec_extension = ExtLane of pack_shape * extension | ExtSplat | ExtZero
+[@@deriving show]
 
 (* Attributes *)
 
diff --git a/src/lib_webassembly/syntax/values.ml b/src/lib_webassembly/syntax/values.ml
index fe6c110bcbeddf15c063e07d42df511ac1cdabf7..9efe5faa13e8798bbc3f82b5e63660a687c0633b 100644
--- a/src/lib_webassembly/syntax/values.ml
+++ b/src/lib_webassembly/syntax/values.ml
@@ -7,12 +7,13 @@ type ('i32, 'i64, 'f32, 'f64) op =
   | I64 of 'i64
   | F32 of 'f32
   | F64 of 'f64
+[@@deriving show]
 
-type 'v128 vecop = V128 of 'v128
+type 'v128 vecop = V128 of 'v128 [@@deriving show]
 
 type num = (I32.t, I64.t, F32.t, F64.t) op
 
-type vec = V128.t vecop
+type vec = V128.t vecop [@@deriving show]
 
 type ref_ = ..
 
diff --git a/src/lib_webassembly/util/source.ml b/src/lib_webassembly/util/source.ml
index fe5ad2021371e6865c311605c9f4888ba4d924b7..d514b5f4bcbca0ddc313818c12a82acffafd37ba 100644
--- a/src/lib_webassembly/util/source.ml
+++ b/src/lib_webassembly/util/source.ml
@@ -1,8 +1,8 @@
-type pos = {file : string; line : int; column : int}
+type pos = {file : string; line : int; column : int} [@@deriving show]
 
-type region = {left : pos; right : pos}
+type region = {left : pos; right : pos} [@@deriving show]
 
-type 'a phrase = {at : region; it : 'a}
+type 'a phrase = {at : region; it : 'a} [@@deriving show]
 
 let ( @@ ) x region = {it = x; at = region}
 
diff --git a/src/lib_webassembly/util/source.mli b/src/lib_webassembly/util/source.mli
index dab908a490a398998dd38490512f372daf976c21..480e59c2bf60687f00e3fa0781bd849e01fee881 100644
--- a/src/lib_webassembly/util/source.mli
+++ b/src/lib_webassembly/util/source.mli
@@ -1,8 +1,8 @@
-type pos = {file : string; line : int; column : int}
+type pos = {file : string; line : int; column : int} [@@deriving show]
 
-type region = {left : pos; right : pos}
+type region = {left : pos; right : pos} [@@deriving show]
 
-type 'a phrase = {at : region; it : 'a}
+type 'a phrase = {at : region; it : 'a} [@@deriving show]
 
 val no_pos : pos