diff --git a/CHANGELOG.md b/CHANGELOG.md
index 35f9a7995a..2d574ccc2a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@
 #### :nail_care: Polish
 
 - Add missing backtick and spaces to `Belt.Map.map` doc comment. https://github.com/rescript-lang/rescript/pull/7632
+- AST: store the attributes directly on function arguments. https://github.com/rescript-lang/rescript/pull/7660
 
 #### :house: Internal
 
diff --git a/compiler/frontend/ast_core_type.ml b/compiler/frontend/ast_core_type.ml
index 1c7c83c835..5e995a5634 100644
--- a/compiler/frontend/ast_core_type.ml
+++ b/compiler/frontend/ast_core_type.ml
@@ -95,7 +95,7 @@ let from_labels ~loc arity labels : t =
   in
   let args =
     Ext_list.map2 labels tyvars (fun label tyvar ->
-        {Parsetree.lbl = Asttypes.Labelled label; typ = tyvar})
+        {Parsetree.attrs = []; lbl = Asttypes.Labelled label; typ = tyvar})
   in
   Typ.arrows ~loc args result_type
 
@@ -131,19 +131,10 @@ let get_curry_arity (ty : t) =
 
 let is_arity_one ty = get_curry_arity ty = 1
 
-type param_type = {
-  label: Asttypes.arg_label;
-  ty: Parsetree.core_type;
-  attr: Parsetree.attributes;
-  loc: loc;
-}
-
-let mk_fn_type (new_arg_types_ty : param_type list) (result : t) : t =
+let mk_fn_type ~loc (new_arg_types_ty : Parsetree.arg list) (result : t) : t =
   let t =
-    Ext_list.fold_right new_arg_types_ty result
-      (fun {label; ty; attr; loc} acc ->
-        Ast_helper.Typ.arrow ~loc ~attrs:attr ~arity:None
-          {lbl = label; typ = ty} acc)
+    Ext_list.fold_right new_arg_types_ty result (fun {lbl; typ; attrs} acc ->
+        Ast_helper.Typ.arrow ~loc ~attrs ~arity:None {attrs = []; lbl; typ} acc)
   in
   match t.ptyp_desc with
   | Ptyp_arrow arr ->
@@ -151,19 +142,11 @@ let mk_fn_type (new_arg_types_ty : param_type list) (result : t) : t =
     {t with ptyp_desc = Ptyp_arrow {arr with arity = Some arity}}
   | _ -> t
 
-let list_of_arrow (ty : t) : t * param_type list =
+let list_of_arrow (ty : t) : t * Parsetree.arg list =
   let rec aux (ty : t) acc =
     match ty.ptyp_desc with
     | Ptyp_arrow {arg; ret; arity} when arity = None || acc = [] ->
-      aux ret
-        (({
-            label = arg.lbl;
-            ty = arg.typ;
-            attr = ty.ptyp_attributes;
-            loc = ty.ptyp_loc;
-          }
-           : param_type)
-        :: acc)
+      aux ret (arg :: acc)
     | Ptyp_poly (_, ty) ->
       (* should not happen? *)
       Bs_syntaxerr.err ty.ptyp_loc Unhandled_poly_type
@@ -173,6 +156,6 @@ let list_of_arrow (ty : t) : t * param_type list =
 
 let add_last_obj (ty : t) (obj : t) =
   let result, params = list_of_arrow ty in
-  mk_fn_type
-    (params @ [{label = Nolabel; ty = obj; attr = []; loc = obj.ptyp_loc}])
+  mk_fn_type ~loc:obj.ptyp_loc
+    (params @ [{lbl = Nolabel; typ = obj; attrs = []}])
     result
diff --git a/compiler/frontend/ast_core_type.mli b/compiler/frontend/ast_core_type.mli
index 15dc6aed32..71f98f450e 100644
--- a/compiler/frontend/ast_core_type.mli
+++ b/compiler/frontend/ast_core_type.mli
@@ -47,16 +47,9 @@ val get_uncurry_arity : t -> int option
    None -- means not a function
 *)
 
-type param_type = {
-  label: Asttypes.arg_label;
-  ty: t;
-  attr: Parsetree.attributes;
-  loc: Location.t;
-}
+val mk_fn_type : loc:Location.t -> Parsetree.arg list -> t -> t
 
-val mk_fn_type : param_type list -> t -> t
-
-val list_of_arrow : t -> t * param_type list
+val list_of_arrow : t -> t * Parsetree.arg list
 (** fails when Ptyp_poly *)
 
 val add_last_obj : t -> t -> t
diff --git a/compiler/frontend/ast_derive_abstract.ml b/compiler/frontend/ast_derive_abstract.ml
index e11ac30a60..aa26fac59a 100644
--- a/compiler/frontend/ast_derive_abstract.ml
+++ b/compiler/frontend/ast_derive_abstract.ml
@@ -84,7 +84,7 @@ let handle_tdcl light (tdcl : Parsetree.type_declaration) :
         ( [],
           (if has_optional_field then
              Ast_helper.Typ.arrow ~loc ~arity:None
-               {lbl = Nolabel; typ = Ast_literal.type_unit ()}
+               {attrs = []; lbl = Nolabel; typ = Ast_literal.type_unit ()}
                core_type
            else core_type),
           [] )
@@ -116,19 +116,19 @@ let handle_tdcl light (tdcl : Parsetree.type_declaration) :
             if is_optional then
               let optional_type = Ast_core_type.lift_option_type pld_type in
               ( Ast_helper.Typ.arrow ~loc:pld_loc ~arity
-                  {lbl = Asttypes.Optional pld_name; typ = pld_type}
+                  {attrs = []; lbl = Asttypes.Optional pld_name; typ = pld_type}
                   maker,
                 Val.mk ~loc:pld_loc
                   (if light then pld_name
                    else {pld_name with txt = pld_name.txt ^ "Get"})
                   ~attrs:get_optional_attrs ~prim
                   (Ast_helper.Typ.arrow ~loc ~arity:(Some 1)
-                     {lbl = Nolabel; typ = core_type}
+                     {attrs = []; lbl = Nolabel; typ = core_type}
                      optional_type)
                 :: acc )
             else
               ( Ast_helper.Typ.arrow ~loc:pld_loc ~arity
-                  {lbl = Asttypes.Labelled pld_name; typ = pld_type}
+                  {attrs = []; lbl = Asttypes.Labelled pld_name; typ = pld_type}
                   maker,
                 Val.mk ~loc:pld_loc
                   (if light then pld_name
@@ -140,7 +140,7 @@ let handle_tdcl light (tdcl : Parsetree.type_declaration) :
                        [External_arg_spec.dummy] Return_identity
                        (Js_get {js_get_name = prim_as_name; js_get_scopes = []}))
                   (Ast_helper.Typ.arrow ~loc ~arity:(Some 1)
-                     {lbl = Nolabel; typ = core_type}
+                     {attrs = []; lbl = Nolabel; typ = core_type}
                      pld_type)
                 :: acc )
           in
@@ -149,9 +149,9 @@ let handle_tdcl light (tdcl : Parsetree.type_declaration) :
             if is_current_field_mutable then
               let setter_type =
                 Ast_helper.Typ.arrow ~arity:(Some 2)
-                  {lbl = Nolabel; typ = core_type}
+                  {attrs = []; lbl = Nolabel; typ = core_type}
                   (Ast_helper.Typ.arrow ~arity:None
-                     {lbl = Nolabel; typ = pld_type} (* setter *)
+                     {attrs = []; lbl = Nolabel; typ = pld_type} (* setter *)
                      (Ast_literal.type_unit ()))
               in
               Val.mk ~loc:pld_loc
diff --git a/compiler/frontend/ast_derive_js_mapper.ml b/compiler/frontend/ast_derive_js_mapper.ml
index 2915025c6f..6130195843 100644
--- a/compiler/frontend/ast_derive_js_mapper.ml
+++ b/compiler/frontend/ast_derive_js_mapper.ml
@@ -69,7 +69,9 @@ let erase_type_str =
   Str.primitive
     (Val.mk ~prim:["%identity"]
        {loc = noloc; txt = erase_type_lit}
-       (Ast_helper.Typ.arrow ~arity:(Some 1) {lbl = Nolabel; typ = any} any))
+       (Ast_helper.Typ.arrow ~arity:(Some 1)
+          {attrs = []; lbl = Nolabel; typ = any}
+          any))
 
 let unsafe_index = "_index"
 
@@ -79,8 +81,11 @@ let unsafe_index_get =
     (Val.mk ~prim:[""]
        {loc = noloc; txt = unsafe_index}
        ~attrs:[Ast_attributes.get_index]
-       (Ast_helper.Typ.arrow ~arity:None {lbl = Nolabel; typ = any}
-          (Ast_helper.Typ.arrow ~arity:None {lbl = Nolabel; typ = any} any)))
+       (Ast_helper.Typ.arrow ~arity:None
+          {attrs = []; lbl = Nolabel; typ = any}
+          (Ast_helper.Typ.arrow ~arity:None
+             {attrs = []; lbl = Nolabel; typ = any}
+             any)))
 
 let unsafe_index_get_exp = Exp.ident {loc = noloc; txt = Lident unsafe_index}
 
@@ -132,7 +137,7 @@ let app1 = Ast_compatible.app1
 let app2 = Ast_compatible.app2
 
 let ( ->~ ) a b =
-  Ast_helper.Typ.arrow ~arity:(Some 1) {lbl = Nolabel; typ = a} b
+  Ast_helper.Typ.arrow ~arity:(Some 1) {attrs = []; lbl = Nolabel; typ = a} b
 
 let raise_when_not_found_ident =
   Longident.Ldot (Lident Primitive_modules.util, "raiseWhenNotFound")
@@ -305,7 +310,7 @@ let init () =
               let to_js_type result =
                 Ast_comb.single_non_rec_val pat_to_js
                   (Ast_helper.Typ.arrow ~arity:(Some 1)
-                     {lbl = Nolabel; typ = core_type}
+                     {attrs = []; lbl = Nolabel; typ = core_type}
                      result)
               in
               let new_type, new_tdcl =
diff --git a/compiler/frontend/ast_derive_projector.ml b/compiler/frontend/ast_derive_projector.ml
index 0b4a4d8611..312c200f63 100644
--- a/compiler/frontend/ast_derive_projector.ml
+++ b/compiler/frontend/ast_derive_projector.ml
@@ -137,7 +137,7 @@ let init () =
                 Ext_list.map label_declarations (fun {pld_name; pld_type} ->
                     Ast_comb.single_non_rec_val ?attrs:gentype_attrs pld_name
                       (Ast_helper.Typ.arrow ~arity:(Some 1)
-                         {lbl = Nolabel; typ = core_type}
+                         {attrs = []; lbl = Nolabel; typ = core_type}
                          pld_type
                          (*arity will alwys be 1 since these are single param functions*)))
               | Ptype_variant constructor_declarations ->
@@ -170,7 +170,8 @@ let init () =
                       {loc; txt = Ext_string.uncapitalize_ascii con_name}
                       (Ext_list.fold_right pcd_args annotate_type (fun x acc ->
                            Ast_helper.Typ.arrow ~arity:None
-                             {lbl = Nolabel; typ = x} acc)
+                             {attrs = []; lbl = Nolabel; typ = x}
+                             acc)
                       |> add_arity ~arity))
               | Ptype_open | Ptype_abstract ->
                 Ast_derive_util.not_applicable tdcl.ptype_loc deriving_name;
diff --git a/compiler/frontend/ast_exp_handle_external.ml b/compiler/frontend/ast_exp_handle_external.ml
index 551a1106e9..c34aff05fc 100644
--- a/compiler/frontend/ast_exp_handle_external.ml
+++ b/compiler/frontend/ast_exp_handle_external.ml
@@ -43,7 +43,7 @@ let handle_external loc (x : string) : Parsetree.expression =
         Ast_external_mk.local_external_apply loc ~pval_prim:["#raw_expr"]
           ~pval_type:
             (Ast_helper.Typ.arrow ~arity:(Some 1)
-               {lbl = Nolabel; typ = Ast_helper.Typ.any ()}
+               {attrs = []; lbl = Nolabel; typ = Ast_helper.Typ.any ()}
                (Ast_helper.Typ.any ()))
           [str_exp];
     }
@@ -72,7 +72,7 @@ let handle_debugger loc (payload : Ast_payload.t) =
     Ast_external_mk.local_external_apply loc ~pval_prim:["%debugger"]
       ~pval_type:
         (Ast_helper.Typ.arrow ~arity:(Some 1)
-           {lbl = Nolabel; typ = Ast_helper.Typ.any ()}
+           {attrs = []; lbl = Nolabel; typ = Ast_helper.Typ.any ()}
            (Ast_literal.type_unit ()))
       [Ast_literal.val_unit ~loc ()]
   | _ ->
@@ -99,7 +99,7 @@ let handle_raw ~kind loc payload =
         Ast_external_mk.local_external_apply loc ~pval_prim:["#raw_expr"]
           ~pval_type:
             (Ast_helper.Typ.arrow ~arity:(Some 1)
-               {lbl = Nolabel; typ = Ast_helper.Typ.any ()}
+               {attrs = []; lbl = Nolabel; typ = Ast_helper.Typ.any ()}
                (Ast_helper.Typ.any ()))
           [exp];
       pexp_attributes =
@@ -128,11 +128,16 @@ let handle_ffi ~loc ~payload =
       let unit = Ast_literal.type_unit ~loc () in
       let rec arrow ~arity =
         if arity = 0 then
-          Ast_helper.Typ.arrow ~arity:None ~loc {lbl = Nolabel; typ = unit} any
+          Ast_helper.Typ.arrow ~arity:None ~loc
+            {attrs = []; lbl = Nolabel; typ = unit}
+            any
         else if arity = 1 then
-          Ast_helper.Typ.arrow ~arity:None ~loc {lbl = Nolabel; typ = any} any
+          Ast_helper.Typ.arrow ~arity:None ~loc
+            {attrs = []; lbl = Nolabel; typ = any}
+            any
         else
-          Ast_helper.Typ.arrow ~loc ~arity:None {lbl = Nolabel; typ = any}
+          Ast_helper.Typ.arrow ~loc ~arity:None
+            {attrs = []; lbl = Nolabel; typ = any}
             (arrow ~arity:(arity - 1))
       in
       match !is_function with
@@ -152,7 +157,7 @@ let handle_ffi ~loc ~payload =
           Ast_external_mk.local_external_apply loc ~pval_prim:["#raw_expr"]
             ~pval_type:
               (Ast_helper.Typ.arrow ~arity:(Some 1)
-                 {lbl = Nolabel; typ = Ast_helper.Typ.any ()}
+                 {attrs = []; lbl = Nolabel; typ = Ast_helper.Typ.any ()}
                  (Ast_helper.Typ.any ()))
             [exp];
         pexp_attributes =
@@ -171,7 +176,7 @@ let handle_raw_structure loc payload =
           Ast_external_mk.local_external_apply loc ~pval_prim:["#raw_stmt"]
             ~pval_type:
               (Ast_helper.Typ.arrow ~arity:(Some 1)
-                 {lbl = Nolabel; typ = Ast_helper.Typ.any ()}
+                 {attrs = []; lbl = Nolabel; typ = Ast_helper.Typ.any ()}
                  (Ast_helper.Typ.any ()))
             [exp];
       }
diff --git a/compiler/frontend/ast_external_process.ml b/compiler/frontend/ast_external_process.ml
index e57e117289..1d43f0a2af 100644
--- a/compiler/frontend/ast_external_process.ml
+++ b/compiler/frontend/ast_external_process.ml
@@ -408,8 +408,7 @@ type response = {
 }
 
 let process_obj (loc : Location.t) (st : external_desc) (prim_name : string)
-    (arg_types_ty : Ast_core_type.param_type list)
-    (result_type : Ast_core_type.t) :
+    (arg_types_ty : Parsetree.arg list) (result_type : Ast_core_type.t) :
     int * Parsetree.core_type * External_ffi_types.t =
   match st with
   | {
@@ -440,11 +439,10 @@ let process_obj (loc : Location.t) (st : external_desc) (prim_name : string)
       Ext_list.fold_right arg_types_ty ([], [], [])
         (fun
           param_type
-          (arg_labels, (arg_types : Ast_core_type.param_type list), result_types)
+          (arg_labels, (arg_types : Parsetree.arg list), result_types)
         ->
-          let arg_label = param_type.label in
-          let loc = param_type.loc in
-          let ty = param_type.ty in
+          let arg_label = param_type.lbl in
+          let ty = param_type.typ in
           let new_arg_label, new_arg_types, output_tys =
             match arg_label with
             | Nolabel -> (
@@ -459,7 +457,7 @@ let process_obj (loc : Location.t) (st : external_desc) (prim_name : string)
             | Labelled {txt = label} -> (
               let field_name =
                 match
-                  Ast_attributes.iter_process_bs_string_as param_type.attr
+                  Ast_attributes.iter_process_bs_string_as param_type.attrs
                 with
                 | Some alias -> alias
                 | None -> label
@@ -518,7 +516,7 @@ let process_obj (loc : Location.t) (st : external_desc) (prim_name : string)
             | Optional {txt = label} -> (
               let field_name =
                 match
-                  Ast_attributes.iter_process_bs_string_as param_type.attr
+                  Ast_attributes.iter_process_bs_string_as param_type.attrs
                 with
                 | Some alias -> alias
                 | None -> label
@@ -594,7 +592,7 @@ let process_obj (loc : Location.t) (st : external_desc) (prim_name : string)
     in
 
     ( List.length new_arg_types_ty,
-      Ast_core_type.mk_fn_type new_arg_types_ty result,
+      Ast_core_type.mk_fn_type ~loc new_arg_types_ty result,
       External_ffi_types.ffi_obj_create arg_kinds )
   | _ -> Location.raise_errorf ~loc "Attribute found that conflicts with %@obj"
 
@@ -942,11 +940,10 @@ let handle_attributes (loc : Bs_loc.t) (type_annotation : Parsetree.core_type)
     let splice = external_desc.splice in
     let arg_type_specs, new_arg_types_ty, arg_type_specs_length =
       Ext_list.fold_right arg_types_ty
-        (([], [], 0)
-          : External_arg_spec.params * Ast_core_type.param_type list * int)
+        (([], [], 0) : External_arg_spec.params * Parsetree.arg list * int)
         (fun param_type (arg_type_specs, arg_types, i) ->
-          let arg_label = param_type.label in
-          let ty = param_type.ty in
+          let arg_label = param_type.lbl in
+          let ty = param_type.typ in
           (if i = 0 && splice then
              match arg_label with
              | Optional _ ->
@@ -1008,7 +1005,7 @@ let handle_attributes (loc : Bs_loc.t) (type_annotation : Parsetree.core_type)
     let return_wrapper =
       check_return_wrapper loc external_desc.return_wrapper result_type
     in
-    let fn_type = Ast_core_type.mk_fn_type new_arg_types_ty result_type in
+    let fn_type = Ast_core_type.mk_fn_type ~loc new_arg_types_ty result_type in
     ( build_uncurried_type ~arity:(List.length new_arg_types_ty) fn_type,
       External_ffi_types.ffi_bs arg_type_specs return_wrapper ffi,
       unused_attrs,
diff --git a/compiler/frontend/ast_typ_uncurry.ml b/compiler/frontend/ast_typ_uncurry.ml
index 6cd1338d29..8ccd76f6d2 100644
--- a/compiler/frontend/ast_typ_uncurry.ml
+++ b/compiler/frontend/ast_typ_uncurry.ml
@@ -32,7 +32,9 @@ let to_method_callback_type loc (mapper : Bs_ast_mapper.mapper)
   let first_arg = mapper.typ mapper first_arg in
   let typ = mapper.typ mapper typ in
   let meth_type =
-    Ast_helper.Typ.arrow ~loc ~arity:None {lbl = label; typ = first_arg} typ
+    Ast_helper.Typ.arrow ~loc ~arity:None
+      {attrs = []; lbl = label; typ = first_arg}
+      typ
   in
   let arity = Ast_core_type.get_uncurry_arity meth_type in
   match arity with
@@ -58,7 +60,9 @@ let to_uncurry_type loc (mapper : Bs_ast_mapper.mapper)
   let typ = mapper.typ mapper typ in
 
   let fn_type =
-    Ast_helper.Typ.arrow ~loc ~arity:None {lbl = label; typ = first_arg} typ
+    Ast_helper.Typ.arrow ~loc ~arity:None
+      {attrs = []; lbl = label; typ = first_arg}
+      typ
   in
   let arity = Ast_core_type.get_uncurry_arity fn_type in
   let fn_type =
diff --git a/compiler/ml/ast_mapper_from0.ml b/compiler/ml/ast_mapper_from0.ml
index 15cadb1bda..4f1f6fff60 100644
--- a/compiler/ml/ast_mapper_from0.ml
+++ b/compiler/ml/ast_mapper_from0.ml
@@ -99,8 +99,8 @@ module T = struct
     | Ptyp_var s -> Typ.var ~loc ~attrs s
     | Ptyp_arrow (lbl, t1, t2) ->
       let lbl = Asttypes.to_arg_label lbl in
-      Typ.arrow ~loc ~attrs ~arity:None
-        {lbl; typ = sub.typ sub t1}
+      Typ.arrow ~loc ~arity:None
+        {attrs; lbl; typ = sub.typ sub t1}
         (sub.typ sub t2)
     | Ptyp_tuple tyl -> Typ.tuple ~loc ~attrs (List.map (sub.typ sub) tyl)
     | Ptyp_constr (lid, tl) -> (
diff --git a/compiler/ml/parsetree.ml b/compiler/ml/parsetree.ml
index 2f39035aed..77194522e8 100644
--- a/compiler/ml/parsetree.ml
+++ b/compiler/ml/parsetree.ml
@@ -73,7 +73,7 @@ and core_type = {
   ptyp_attributes: attributes; (* ... [@id1] [@id2] *)
 }
 
-and arg = {lbl: arg_label; typ: core_type}
+and arg = {attrs: attributes; lbl: arg_label; typ: core_type}
 
 and core_type_desc =
   | Ptyp_any (*  _ *)
diff --git a/compiler/ml/pprintast.ml b/compiler/ml/pprintast.ml
index 78b4a691b8..ff7f3f8c70 100644
--- a/compiler/ml/pprintast.ml
+++ b/compiler/ml/pprintast.ml
@@ -285,11 +285,15 @@ let tyvar f str = pp f "'%s" str
 let tyvar_loc f str = pp f "'%s" str.txt
 let string_quot f x = pp f "`%s" x
 
-let rec type_with_label ctxt f (label, c) =
-  match label with
-  | Nolabel -> core_type1 ctxt f c (* otherwise parenthesize *)
-  | Labelled {txt = s} -> pp f "%s:%a" s (core_type1 ctxt) c
-  | Optional {txt = s} -> pp f "?%s:%a" s (core_type1 ctxt) c
+let rec type_with_label ctxt f arg =
+  match arg.lbl with
+  | Nolabel ->
+    pp f "%a%a" (core_type1 ctxt) arg.typ (attributes ctxt) arg.attrs
+    (* otherwise parenthesize *)
+  | Labelled {txt = s} ->
+    pp f "%s:%a%a" s (core_type1 ctxt) arg.typ (attributes ctxt) arg.attrs
+  | Optional {txt = s} ->
+    pp f "?%s:%a%a" s (core_type1 ctxt) arg.typ (attributes ctxt) arg.attrs
 
 and core_type ctxt f x =
   if x.ptyp_attributes <> [] then
@@ -300,7 +304,7 @@ and core_type ctxt f x =
     match x.ptyp_desc with
     | Ptyp_arrow {arg; ret; arity} ->
       pp f "@[<2>%a@;->@;%a%s@]" (* FIXME remove parens later *)
-        (type_with_label ctxt) (arg.lbl, arg.typ) (core_type ctxt) ret
+        (type_with_label ctxt) arg (core_type ctxt) ret
         (match arity with
         | None -> ""
         | Some n -> " (a:" ^ string_of_int n ^ ")")
diff --git a/compiler/ml/printtyped.ml b/compiler/ml/printtyped.ml
index efcd560dcc..064f0ab55c 100644
--- a/compiler/ml/printtyped.ml
+++ b/compiler/ml/printtyped.ml
@@ -152,6 +152,7 @@ let rec core_type i ppf x =
   | Ttyp_arrow (arg, ret, _) ->
     line i ppf "Ttyp_arrow\n";
     arg_label i ppf arg.lbl;
+    attributes i ppf arg.attrs;
     core_type i ppf arg.typ;
     core_type i ppf ret
   | Ttyp_tuple l ->
diff --git a/compiler/ml/typedtree.ml b/compiler/ml/typedtree.ml
index 97bfe3848a..9ef328be4a 100644
--- a/compiler/ml/typedtree.ml
+++ b/compiler/ml/typedtree.ml
@@ -303,7 +303,7 @@ and core_type = {
   ctyp_attributes: attribute list;
 }
 
-and arg = {lbl: Noloc.arg_label; typ: core_type}
+and arg = {attrs: attributes; lbl: Noloc.arg_label; typ: core_type}
 
 and core_type_desc =
   | Ttyp_any
diff --git a/compiler/ml/typedtree.mli b/compiler/ml/typedtree.mli
index 71292362dc..6e6b1c5159 100644
--- a/compiler/ml/typedtree.mli
+++ b/compiler/ml/typedtree.mli
@@ -409,7 +409,7 @@ and core_type = {
   ctyp_attributes: attributes;
 }
 
-and arg = {lbl: Noloc.arg_label; typ: core_type}
+and arg = {attrs: attributes; lbl: Noloc.arg_label; typ: core_type}
 
 and core_type_desc =
   | Ttyp_any
diff --git a/compiler/ml/typetexp.ml b/compiler/ml/typetexp.ml
index 77cff06785..16308442dc 100644
--- a/compiler/ml/typetexp.ml
+++ b/compiler/ml/typetexp.ml
@@ -329,7 +329,7 @@ and transl_type_aux env policy styp =
       else ty1
     in
     let ty = newty (Tarrow ({lbl; typ = ty1}, cty2.ctyp_type, Cok, arity)) in
-    ctyp (Ttyp_arrow ({lbl; typ = cty1}, cty2, arity)) ty
+    ctyp (Ttyp_arrow ({attrs = arg.attrs; lbl; typ = cty1}, cty2, arity)) ty
   | Ptyp_tuple stl ->
     assert (List.length stl >= 2);
     let ctys = List.map (transl_type env policy) stl in
diff --git a/compiler/syntax/src/jsx_v4.ml b/compiler/syntax/src/jsx_v4.ml
index e3391a63f3..b7ec8b15e3 100644
--- a/compiler/syntax/src/jsx_v4.ml
+++ b/compiler/syntax/src/jsx_v4.ml
@@ -918,20 +918,16 @@ let transform_structure_item ~config item =
         |> Option.map Jsx_common.typ_vars_of_core_type
         |> Option.value ~default:[]
       in
-      let rec get_prop_types types
-          ({ptyp_loc; ptyp_desc; ptyp_attributes} as full_type) =
+      let rec get_prop_types types ({ptyp_loc; ptyp_desc} as full_type) =
         match ptyp_desc with
         | Ptyp_arrow {arg; ret = {ptyp_desc = Ptyp_arrow _} as typ2}
           when is_labelled arg.lbl || is_optional arg.lbl ->
-          get_prop_types
-            ((arg.lbl, ptyp_attributes, ptyp_loc, arg.typ) :: types)
-            typ2
+          get_prop_types ((arg.lbl, arg.attrs, ptyp_loc, arg.typ) :: types) typ2
         | Ptyp_arrow {arg = {lbl = Nolabel}; ret} -> get_prop_types types ret
         | Ptyp_arrow {arg; ret = return_value}
           when is_labelled arg.lbl || is_optional arg.lbl ->
           ( return_value,
-            (arg.lbl, ptyp_attributes, return_value.ptyp_loc, arg.typ) :: types
-          )
+            (arg.lbl, arg.attrs, return_value.ptyp_loc, arg.typ) :: types )
         | _ -> (full_type, types)
       in
       let inner_type, prop_types = get_prop_types [] pval_type in
@@ -1027,9 +1023,7 @@ let transform_signature_item ~config item =
         match ptyp_desc with
         | Ptyp_arrow {arg; ret = {ptyp_desc = Ptyp_arrow _} as rest}
           when is_optional arg.lbl || is_labelled arg.lbl ->
-          get_prop_types
-            ((arg.lbl, arg.typ.ptyp_attributes, ptyp_loc, arg.typ) :: types)
-            rest
+          get_prop_types ((arg.lbl, arg.attrs, ptyp_loc, arg.typ) :: types) rest
         | Ptyp_arrow
             {
               arg =
@@ -1045,8 +1039,7 @@ let transform_signature_item ~config item =
         | Ptyp_arrow {arg; ret = return_value}
           when is_optional arg.lbl || is_labelled arg.lbl ->
           ( return_value,
-            (arg.lbl, arg.typ.ptyp_attributes, return_value.ptyp_loc, arg.typ)
-            :: types )
+            (arg.lbl, arg.attrs, return_value.ptyp_loc, arg.typ) :: types )
         | _ -> (full_type, types)
       in
       let inner_type, prop_types = get_prop_types [] pval_type in
diff --git a/compiler/syntax/src/res_core.ml b/compiler/syntax/src/res_core.ml
index 1d573460c4..cb4096661e 100644
--- a/compiler/syntax/src/res_core.ml
+++ b/compiler/syntax/src/res_core.ml
@@ -4039,7 +4039,8 @@ and parse_poly_type_expr ?current_type_name_path ?inline_types_context p =
         let typ = Ast_helper.Typ.var ~loc:var.loc var.txt in
         let return_type = parse_typ_expr ~alias:false p in
         let loc = mk_loc typ.Parsetree.ptyp_loc.loc_start p.prev_end_pos in
-        Ast_helper.Typ.arrow ~loc ~arity:(Some 1) {lbl = Nolabel; typ}
+        Ast_helper.Typ.arrow ~loc ~arity:(Some 1)
+          {attrs = []; lbl = Nolabel; typ}
           return_type
       | _ -> Ast_helper.Typ.var ~loc:var.loc var.txt)
     | _ -> assert false)
@@ -4400,7 +4401,7 @@ and parse_es6_arrow_type ~attrs p =
     Parser.expect EqualGreater p;
     let return_type = parse_typ_expr ~alias:false p in
     let loc = mk_loc start_pos p.prev_end_pos in
-    Ast_helper.Typ.arrow ~loc ~attrs ~arity:None {lbl; typ} return_type
+    Ast_helper.Typ.arrow ~loc ~arity:None {attrs; lbl; typ} return_type
   | DocComment _ -> assert false
   | _ ->
     let parameters = parse_type_parameters p in
@@ -4429,7 +4430,7 @@ and parse_es6_arrow_type ~attrs p =
             | _ -> arity
           in
           let t_arg =
-            Ast_helper.Typ.arrow ~loc ~attrs ~arity:None {lbl = arg_lbl; typ} t
+            Ast_helper.Typ.arrow ~loc ~arity:None {attrs; lbl = arg_lbl; typ} t
           in
           if param_num = 1 then
             (param_num - 1, Ast_uncurried.uncurried_type ~arity t_arg, 1)
@@ -4493,7 +4494,9 @@ and parse_arrow_type_rest ~es6_arrow ~start_pos typ p =
     Parser.next p;
     let return_type = parse_typ_expr ~alias:false p in
     let loc = mk_loc start_pos p.prev_end_pos in
-    Ast_helper.Typ.arrow ~loc ~arity:(Some 1) {lbl = Nolabel; typ} return_type
+    Ast_helper.Typ.arrow ~loc ~arity:(Some 1)
+      {attrs = []; lbl = Nolabel; typ}
+      return_type
   | _ -> typ
 
 and parse_typ_expr_region p =
@@ -5151,7 +5154,8 @@ and parse_type_equation_or_constr_decl p =
         let return_type = parse_typ_expr ~alias:false p in
         let loc = mk_loc uident_start_pos p.prev_end_pos in
         let arrow_type =
-          Ast_helper.Typ.arrow ~loc ~arity:(Some 1) {lbl = Nolabel; typ}
+          Ast_helper.Typ.arrow ~loc ~arity:(Some 1)
+            {attrs = []; lbl = Nolabel; typ}
             return_type
         in
         let typ = parse_type_alias p arrow_type in
diff --git a/compiler/syntax/src/res_parsetree_viewer.ml b/compiler/syntax/src/res_parsetree_viewer.ml
index 1deb497adb..f7264f6fb6 100644
--- a/compiler/syntax/src/res_parsetree_viewer.ml
+++ b/compiler/syntax/src/res_parsetree_viewer.ml
@@ -4,32 +4,22 @@ let arrow_type ?(max_arity = max_int) ct =
   let has_as_attr attrs =
     Ext_list.exists attrs (fun (x, _) -> x.Asttypes.txt = "as")
   in
-  let rec process attrs_before acc typ arity =
+  let rec process attrs_before acc typ max_arity =
     match typ with
-    | _ when arity < 0 -> (attrs_before, List.rev acc, typ)
-    | {ptyp_desc = Ptyp_arrow {arity = Some _}; ptyp_attributes = []}
+    | _ when max_arity < 0 -> (attrs_before, List.rev acc, typ)
+    | {ptyp_desc = Ptyp_arrow {arity = Some _; arg = {attrs = []}}}
       when acc <> [] ->
       (attrs_before, List.rev acc, typ)
-    | {
-     ptyp_desc = Ptyp_arrow {arg = {lbl = Nolabel} as arg; ret};
-     ptyp_attributes = [];
-    } ->
-      let arg = ([], arg.lbl, arg.typ) in
-      process attrs_before (arg :: acc) ret (arity - 1)
-    | {
-     ptyp_desc = Ptyp_arrow {arg = {lbl = Nolabel}};
-     ptyp_attributes = [({txt = "bs"}, _)];
-    } ->
-      (* stop here, the uncurried attribute always indicates the beginning of an arrow function
-       * e.g. `(. int) => (. int)` instead of `(. int, . int)` *)
-      (attrs_before, List.rev acc, typ)
+    | {ptyp_desc = Ptyp_arrow {arg = {lbl = Nolabel; attrs = []} as arg; ret}}
+      ->
+      process attrs_before (arg :: acc) ret (max_arity - 1)
     | {ptyp_desc = Ptyp_arrow {arg = {lbl = Nolabel}}; ptyp_attributes = _attrs}
       as return_type ->
       let args = List.rev acc in
       (attrs_before, args, return_type)
     | {
      ptyp_desc = Ptyp_arrow {arg = {lbl = Labelled _ | Optional _} as arg; ret};
-     ptyp_attributes = attrs;
+     ptyp_attributes = _attrs;
     } ->
       (* Res_core.parse_es6_arrow_type has a workaround that removed an extra arity for the function if the
          argument is a Ptyp_any with @as attribute i.e. ~x: @as(`{prop: value}`) _.
@@ -40,16 +30,14 @@ let arrow_type ?(max_arity = max_int) ct =
         match arg.typ with
         | {ptyp_desc = Ptyp_any; ptyp_attributes = attrs1}
           when has_as_attr attrs1 ->
-          arity
-        | _ -> arity - 1
+          max_arity
+        | _ -> max_arity - 1
       in
-      let arg = (attrs, arg.lbl, arg.typ) in
       process attrs_before (arg :: acc) ret arity
     | typ -> (attrs_before, List.rev acc, typ)
   in
   match ct with
-  | {ptyp_desc = Ptyp_arrow {arg = {lbl = Nolabel}}; ptyp_attributes = attrs1}
-    as typ ->
+  | {ptyp_desc = Ptyp_arrow _; ptyp_attributes = attrs1} as typ ->
     process attrs1 [] {typ with ptyp_attributes = []} max_arity
   | typ -> process [] [] typ max_arity
 
diff --git a/compiler/syntax/src/res_parsetree_viewer.mli b/compiler/syntax/src/res_parsetree_viewer.mli
index d697d9fa3c..c50e3f2ce8 100644
--- a/compiler/syntax/src/res_parsetree_viewer.mli
+++ b/compiler/syntax/src/res_parsetree_viewer.mli
@@ -4,9 +4,7 @@
 val arrow_type :
   ?max_arity:int ->
   Parsetree.core_type ->
-  Parsetree.attributes
-  * (Parsetree.attributes * Asttypes.arg_label * Parsetree.core_type) list
-  * Parsetree.core_type
+  Parsetree.attributes * Parsetree.arg list * Parsetree.core_type
 
 val functor_type :
   Parsetree.module_type ->
diff --git a/compiler/syntax/src/res_printer.ml b/compiler/syntax/src/res_printer.ml
index 17dd46f102..0dc8e49630 100644
--- a/compiler/syntax/src/res_printer.ml
+++ b/compiler/syntax/src/res_printer.ml
@@ -1702,7 +1702,7 @@ and print_typ_expr ?inline_record_definitions ~(state : State.t)
     in
     match args with
     | [] -> Doc.nil
-    | [([], Nolabel, n)] ->
+    | [{attrs = []; lbl = Nolabel; typ}] ->
       let has_attrs_before = not (attrs_before = []) in
       let attrs =
         if has_attrs_before then
@@ -1710,8 +1710,8 @@ and print_typ_expr ?inline_record_definitions ~(state : State.t)
         else Doc.nil
       in
       let typ_doc =
-        let doc = print_typ_expr ~state n cmt_tbl in
-        match n.ptyp_desc with
+        let doc = print_typ_expr ~state typ cmt_tbl in
+        match typ.ptyp_desc with
         | Ptyp_arrow _ | Ptyp_tuple _ | Ptyp_alias _ -> add_parens doc
         | _ -> doc
       in
@@ -2054,7 +2054,7 @@ and print_object_field ~state (field : Parsetree.object_field) cmt_tbl =
 (* es6 arrow type arg
  * type t = (~foo: string, ~bar: float=?, unit) => unit
  * i.e. ~foo: string, ~bar: float *)
-and print_type_parameter ~state (attrs, lbl, typ) cmt_tbl =
+and print_type_parameter ~state {attrs; lbl; typ} cmt_tbl =
   (* Converting .ml code to .res requires processing uncurried attributes *)
   let attrs = print_attributes ~state attrs cmt_tbl in
   let label =
diff --git a/tests/syntax_tests/data/parsing/grammar/typexpr/expected/es6Arrow.res.txt b/tests/syntax_tests/data/parsing/grammar/typexpr/expected/es6Arrow.res.txt
index aa42f44491..47f23df499 100644
--- a/tests/syntax_tests/data/parsing/grammar/typexpr/expected/es6Arrow.res.txt
+++ b/tests/syntax_tests/data/parsing/grammar/typexpr/expected/es6Arrow.res.txt
@@ -22,13 +22,13 @@ type nonrec t = f:(int -> string (a:1)) -> float (a:1)
 type nonrec t = f:(int -> string (a:1)) -> float
 type nonrec t = f:int -> string -> float (a:1)
 type nonrec t =
-  ((a:int -> ((b:int -> ((float)[@attr ]) -> unit)[@attrBeforeLblB ]) (a:3))
-  [@attrBeforeLblA ])
+  a:int[@attrBeforeLblA ] ->
+    b:int[@attrBeforeLblB ] -> ((float)[@attr ]) -> unit (a:3)
 type nonrec t =
   ((a:int ->
       ((b:int -> ((float)[@attr ]) -> unit (a:1) (a:1))[@attrBeforeLblB ]) (a:1))
   [@attrBeforeLblA ])
-type nonrec t = ((a:int -> unit)[@attr ])
+type nonrec t = a:int[@attr ] -> unit
 type nonrec 'a getInitialPropsFn =
   < query: string dict  ;req: 'a Js.t Js.Nullable.t   >  ->
     'a Js.t Js.Promise.t (a:1)
\ No newline at end of file
diff --git a/tests/syntax_tests/data/ppx/react/expected/mangleKeyword.res.txt b/tests/syntax_tests/data/ppx/react/expected/mangleKeyword.res.txt
index 1103c8267d..4413b38798 100644
--- a/tests/syntax_tests/data/ppx/react/expected/mangleKeyword.res.txt
+++ b/tests/syntax_tests/data/ppx/react/expected/mangleKeyword.res.txt
@@ -15,7 +15,7 @@ module C4A1 = {
   @res.jsxComponentProps @live
   type props<'T_open, 'T_type> = {@as("open") _open: 'T_open, @as("type") _type: 'T_type}
 
-  external make: @as("open") React.componentLike<props<string, string>, React.element> = "default"
+  external make: React.componentLike<props<string, string>, React.element> = "default"
 }
 
 let c4a0 = React.jsx(C4A0.make, {_open: "x", _type: "t"})
diff --git a/tests/syntax_tests/data/printer/typexpr/expected/arrow.res.txt b/tests/syntax_tests/data/printer/typexpr/expected/arrow.res.txt
index 0392485cb0..cd0180e929 100644
--- a/tests/syntax_tests/data/printer/typexpr/expected/arrow.res.txt
+++ b/tests/syntax_tests/data/printer/typexpr/expected/arrow.res.txt
@@ -132,7 +132,7 @@ type t = @attr (foo, @attr2 ~f: bar, @attr3 ~f: baz) => unit
 type t = @attr (string => @attr (int => unit))
 type t = @attr (string, int) => @attr (int, float) => unit
 type t = @attr (int => @attr (int, float) => @attr (unit => unit => unit))
-type t = (@attr @attr2 ~f: int, @attr3 ~g: float) => unit
+type t = @attr (@attr2 ~f: int, @attr3 ~g: float) => unit
 
 type f = (
   @attr @attr @attr @attr @attr @attr @attr @attr @attr ~f: superLong,