diff --git a/analysis/src/CompletionFrontEnd.ml b/analysis/src/CompletionFrontEnd.ml
index e2d4a51f46..b1717ae893 100644
--- a/analysis/src/CompletionFrontEnd.ml
+++ b/analysis/src/CompletionFrontEnd.ml
@@ -267,12 +267,14 @@ let rec exprToContextPathInner ~(inJsxContext : bool) (e : Parsetree.expression)
           };
         args =
           [(_, lhs); (_, {pexp_desc = Pexp_apply {funct = d; args; partial}})];
+        transformed_jsx;
       } ->
     (* Transform away pipe with apply call *)
     exprToContextPath ~inJsxContext
       {
         pexp_desc =
-          Pexp_apply {funct = d; args = (Nolabel, lhs) :: args; partial};
+          Pexp_apply
+            {funct = d; args = (Nolabel, lhs) :: args; partial; transformed_jsx};
         pexp_loc;
         pexp_attributes;
       }
@@ -284,6 +286,7 @@ let rec exprToContextPathInner ~(inJsxContext : bool) (e : Parsetree.expression)
             (_, lhs); (_, {pexp_desc = Pexp_ident id; pexp_loc; pexp_attributes});
           ];
         partial;
+        transformed_jsx;
       } ->
     (* Transform away pipe with identifier *)
     exprToContextPath ~inJsxContext
@@ -294,6 +297,7 @@ let rec exprToContextPathInner ~(inJsxContext : bool) (e : Parsetree.expression)
               funct = {pexp_desc = Pexp_ident id; pexp_loc; pexp_attributes};
               args = [(Nolabel, lhs)];
               partial;
+              transformed_jsx;
             };
         pexp_loc;
         pexp_attributes;
diff --git a/compiler/core/js_call_info.ml b/compiler/core/js_call_info.ml
index 547f03c7f8..6412d91b1f 100644
--- a/compiler/core/js_call_info.ml
+++ b/compiler/core/js_call_info.ml
@@ -33,10 +33,12 @@ type call_info =
    {[ fun x y -> (f x y) === f ]} when [f] is an atom
 *)
 
-type t = {call_info: call_info; arity: arity}
+type t = {call_info: call_info; arity: arity; call_transformed_jsx: bool}
 
-let dummy = {arity = NA; call_info = Call_na}
+let dummy = {arity = NA; call_info = Call_na; call_transformed_jsx = false}
 
-let builtin_runtime_call = {arity = Full; call_info = Call_builtin_runtime}
+let builtin_runtime_call =
+  {arity = Full; call_info = Call_builtin_runtime; call_transformed_jsx = false}
 
-let ml_full_call = {arity = Full; call_info = Call_ml}
+let ml_full_call =
+  {arity = Full; call_info = Call_ml; call_transformed_jsx = false}
diff --git a/compiler/core/js_call_info.mli b/compiler/core/js_call_info.mli
index 0381c0cd2b..1977426737 100644
--- a/compiler/core/js_call_info.mli
+++ b/compiler/core/js_call_info.mli
@@ -35,7 +35,7 @@ type call_info =
    {[ fun x y -> f x y === f ]} when [f] is an atom
 *)
 
-type t = {call_info: call_info; arity: arity}
+type t = {call_info: call_info; arity: arity; call_transformed_jsx: bool}
 
 val dummy : t
 
diff --git a/compiler/core/js_dump.ml b/compiler/core/js_dump.ml
index bc174e7dd5..dba419bd18 100644
--- a/compiler/core/js_dump.ml
+++ b/compiler/core/js_dump.ml
@@ -524,6 +524,45 @@ and expression_desc cxt ~(level : int) f x : cxt =
          when Ext_list.length_equal el i
        ]}
     *)
+  | Call (e, el, {call_transformed_jsx = true}) -> (
+    match el with
+    | [
+     tag;
+     {
+       expression_desc =
+         Caml_block (el, _mutable_flag, _, Lambda.Blk_record {fields});
+     };
+    ] ->
+      let fields =
+        Ext_list.array_list_filter_map fields el (fun (f, opt) x ->
+            match x.expression_desc with
+            | Undefined _ when opt -> None
+            | _ -> Some (f, x))
+      in
+      print_jsx cxt ~level f tag fields
+    | [
+     tag;
+     {
+       expression_desc =
+         Caml_block (el, _mutable_flag, _, Lambda.Blk_record {fields});
+     };
+     key;
+    ] ->
+      let fields =
+        Ext_list.array_list_filter_map fields el (fun (f, opt) x ->
+            match x.expression_desc with
+            | Undefined _ when opt -> None
+            | _ -> Some (f, x))
+      in
+      let fields = ("key", key) :: fields in
+      print_jsx cxt ~level f tag fields
+    | _ ->
+      expression_desc cxt ~level f
+        (Call
+           ( e,
+             el,
+             {call_transformed_jsx = false; arity = Full; call_info = Call_ml}
+           )))
   | Call (e, el, info) ->
     P.cond_paren_group f (level > 15) (fun _ ->
         P.group f 0 (fun _ ->
@@ -681,6 +720,7 @@ and expression_desc cxt ~(level : int) f x : cxt =
     P.cond_paren_group f (level > 12) (fun _ ->
         let cxt = expression ~level:0 cxt f prop in
         P.string f " in ";
+        P.string f " in ";
         expression ~level:0 cxt f obj)
   | Typeof e ->
     P.string f "typeof";
@@ -956,6 +996,58 @@ and expression_desc cxt ~(level : int) f x : cxt =
         P.string f "...";
         expression ~level:13 cxt f e)
 
+and print_jsx cxt ~(level : int) f (tag : J.expression)
+    (fields : (string * J.expression) list) : cxt =
+  let print_tag () =
+    match tag.expression_desc with
+    | J.Str {txt} -> P.string f txt
+    (* fragment *)
+    | J.Var (J.Qualified ({id = {name = "JsxRuntime"}}, Some "Fragment")) -> ()
+    | _ ->
+      let _ = expression ~level cxt f tag in
+      ()
+  in
+  let children_opt =
+    List.find_map (fun (n, e) -> if n = "children" then Some e else None) fields
+  in
+  let print_props () =
+    let props = List.filter (fun (n, _) -> n <> "children") fields in
+    if not (List.is_empty props) then
+      (List.iter (fun (n, x) ->
+           P.space f;
+           P.string f n;
+           P.string f "=";
+           P.string f "{";
+           let _ = expression ~level:0 cxt f x in
+           P.string f "}"))
+        props
+  in
+  (match children_opt with
+  | None ->
+    P.string f "<";
+    print_tag ();
+    print_props ();
+    P.string f "/>"
+  | Some children ->
+    let child_is_jsx =
+      match children.expression_desc with
+      | J.Call (_, _, {call_transformed_jsx = is_jsx}) -> is_jsx
+      | _ -> false
+    in
+
+    P.string f "<";
+    print_tag ();
+    print_props ();
+    P.string f ">";
+    if not child_is_jsx then P.string f "{";
+    let _ = expression ~level cxt f children in
+    if not child_is_jsx then P.string f "}";
+    P.string f "</";
+    print_tag ();
+    P.string f ">");
+
+  cxt
+
 and property_name_and_value_list cxt f (l : J.property_map) =
   iter_lst cxt f l
     (fun cxt f (pn, e) ->
diff --git a/compiler/core/jsx_help.ml b/compiler/core/jsx_help.ml
new file mode 100644
index 0000000000..a1a8f1c650
--- /dev/null
+++ b/compiler/core/jsx_help.ml
@@ -0,0 +1,47 @@
+let lambda_tag_info_to_string (e : Lambda.tag_info) =
+  match e with
+  | Lambda.Blk_constructor _ -> "Blk_constructor"
+  | Lambda.Blk_record_inlined _ -> "Blk_record_inlined"
+  | Lambda.Blk_tuple -> "Blk_tuple"
+  | Lambda.Blk_poly_var _ -> "Blk_poly_var"
+  | Lambda.Blk_record _ -> "Blk_record"
+  | Lambda.Blk_module _ -> "Blk_module"
+  | Lambda.Blk_module_export _ -> "Blk_module_export"
+  | Lambda.Blk_extension -> "Blk_extension"
+  | Lambda.Blk_some -> "Blk_some"
+  | Lambda.Blk_some_not_nested -> "Blk_some_not_nested"
+  | Lambda.Blk_record_ext _ -> "Blk_record_ext"
+  | Lambda.Blk_lazy_general -> "Blk_lazy_general"
+
+let j_exp_to_string (e : J.expression) =
+  match e.J.expression_desc with
+  | J.Object _ -> "Object"
+  | J.Str _ -> "String"
+  | J.Var _ -> "Var"
+  | J.Call _ -> "Call"
+  | J.Fun _ -> "Fun"
+  | J.Array _ -> "Array"
+  | J.Bin _ -> "Bin"
+  | J.Cond _ -> "Cond"
+  | J.New _ -> "New"
+  | J.Seq _ -> "Seq"
+  | J.Number _ -> "Number"
+  | J.Bool _ -> "Bool"
+  | J.Null -> "Null"
+  | J.Undefined _ -> "Undefined"
+  | J.Is_null_or_undefined _ -> "Is_null_or_undefined"
+  | J.Js_not _ -> "Js_not"
+  | J.Typeof _ -> "Typeof"
+  | J.String_index _ -> "String_index"
+  | J.Array_index _ -> "Array_index"
+  | J.Static_index _ -> "Static_index"
+  | J.Length _ -> "Length"
+  | J.Caml_block (_, _, _, tag) ->
+    Format.sprintf "Caml_block (%s)" (lambda_tag_info_to_string tag)
+  | J.Caml_block_tag _ -> "Caml_block_tag"
+  | J.Tagged_template _ -> "Tagged_template"
+  | J.Optional_block _ -> "Optional_block"
+  | J.Spread _ -> "Spread"
+  | J.Await _ -> "Await"
+  | J.Raw_js_code _ -> "Raw_js_code"
+  | _ -> "Other"
diff --git a/compiler/core/lam.ml b/compiler/core/lam.ml
index 77f991e181..1c20bb2e8e 100644
--- a/compiler/core/lam.ml
+++ b/compiler/core/lam.ml
@@ -81,7 +81,12 @@ module Types = struct
   *)
   and prim_info = {primitive: Lam_primitive.t; args: t list; loc: Location.t}
 
-  and apply = {ap_func: t; ap_args: t list; ap_info: ap_info}
+  and apply = {
+    ap_func: t;
+    ap_args: t list;
+    ap_info: ap_info;
+    ap_transformed_jsx: bool;
+  }
 
   and t =
     | Lvar of ident
@@ -121,7 +126,12 @@ module X = struct
     loc: Location.t;
   }
 
-  and apply = Types.apply = {ap_func: t; ap_args: t list; ap_info: ap_info}
+  and apply = Types.apply = {
+    ap_func: t;
+    ap_args: t list;
+    ap_info: ap_info;
+    ap_transformed_jsx: bool;
+  }
 
   and lfunction = Types.lfunction = {
     arity: int;
@@ -159,10 +169,10 @@ include Types
 let inner_map (l : t) (f : t -> X.t) : X.t =
   match l with
   | Lvar (_ : ident) | Lconst (_ : Lam_constant.t) -> ((* Obj.magic *) l : X.t)
-  | Lapply {ap_func; ap_args; ap_info} ->
+  | Lapply {ap_func; ap_args; ap_info; ap_transformed_jsx} ->
     let ap_func = f ap_func in
     let ap_args = Ext_list.map ap_args f in
-    Lapply {ap_func; ap_args; ap_info}
+    Lapply {ap_func; ap_args; ap_info; ap_transformed_jsx}
   | Lfunction {body; arity; params; attr} ->
     let body = f body in
     Lfunction {body; arity; params; attr}
@@ -279,7 +289,7 @@ let rec is_eta_conversion_exn params inner_args outer_args : t list =
   | _, _, _ -> raise_notrace Not_simple_form
 
 (** FIXME: more robust inlining check later, we should inline it before we add stub code*)
-let rec apply fn args (ap_info : ap_info) : t =
+let rec apply ?(ap_transformed_jsx = false) fn args (ap_info : ap_info) : t =
   match fn with
   | Lfunction
       {
@@ -300,7 +310,7 @@ let rec apply fn args (ap_info : ap_info) : t =
       Lprim
         {primitive = wrap; args = [Lprim {primitive_call with args; loc}]; loc}
     | exception Not_simple_form ->
-      Lapply {ap_func = fn; ap_args = args; ap_info})
+      Lapply {ap_func = fn; ap_args = args; ap_info; ap_transformed_jsx})
   | Lfunction
       {
         params;
@@ -308,7 +318,8 @@ let rec apply fn args (ap_info : ap_info) : t =
       } -> (
     match is_eta_conversion_exn params inner_args args with
     | args -> Lprim {primitive_call with args; loc = ap_info.ap_loc}
-    | exception _ -> Lapply {ap_func = fn; ap_args = args; ap_info})
+    | exception _ ->
+      Lapply {ap_func = fn; ap_args = args; ap_info; ap_transformed_jsx})
   | Lfunction
       {
         params;
@@ -321,17 +332,17 @@ let rec apply fn args (ap_info : ap_info) : t =
     | args ->
       Lsequence (Lprim {primitive_call with args; loc = ap_info.ap_loc}, const)
     | exception _ ->
-      Lapply {ap_func = fn; ap_args = args; ap_info}
+      Lapply {ap_func = fn; ap_args = args; ap_info; ap_transformed_jsx}
       (* | Lfunction {params;body} when Ext_list.same_length params args ->
           Ext_list.fold_right2 (fun p arg acc ->
             Llet(Strict,p,arg,acc)
           ) params args body *)
       (* TODO: more rigirous analysis on [let_kind] *))
   | Llet (kind, id, e, (Lfunction _ as fn)) ->
-    Llet (kind, id, e, apply fn args ap_info)
+    Llet (kind, id, e, apply fn args ap_info ~ap_transformed_jsx)
   (* | Llet (kind0, id0, e0, Llet (kind,id, e, (Lfunction _ as fn))) ->
      Llet(kind0,id0,e0,Llet (kind, id, e, apply fn args loc status)) *)
-  | _ -> Lapply {ap_func = fn; ap_args = args; ap_info}
+  | _ -> Lapply {ap_func = fn; ap_args = args; ap_info; ap_transformed_jsx}
 
 let rec eq_approx (l1 : t) (l2 : t) =
   match l1 with
@@ -712,10 +723,12 @@ let result_wrap loc (result_type : External_ffi_types.return_wrapper) result =
     prim ~primitive:Pundefined_to_opt ~args:[result] loc
   | Return_unset | Return_identity -> result
 
-let handle_bs_non_obj_ffi (arg_types : External_arg_spec.params)
+let handle_bs_non_obj_ffi ?(transformed_jsx = false)
+    (arg_types : External_arg_spec.params)
     (result_type : External_ffi_types.return_wrapper) ffi args loc prim_name
     ~dynamic_import =
   result_wrap loc result_type
     (prim
-       ~primitive:(Pjs_call {prim_name; arg_types; ffi; dynamic_import})
+       ~primitive:
+         (Pjs_call {prim_name; arg_types; ffi; dynamic_import; transformed_jsx})
        ~args loc)
diff --git a/compiler/core/lam.mli b/compiler/core/lam.mli
index 66858ac2a4..560d247669 100644
--- a/compiler/core/lam.mli
+++ b/compiler/core/lam.mli
@@ -41,7 +41,12 @@ type lambda_switch = {
   sw_names: Ast_untagged_variants.switch_names option;
 }
 
-and apply = private {ap_func: t; ap_args: t list; ap_info: ap_info}
+and apply = private {
+  ap_func: t;
+  ap_args: t list;
+  ap_info: ap_info;
+  ap_transformed_jsx: bool;
+}
 
 and lfunction = {
   arity: int;
@@ -85,6 +90,7 @@ and t = private
 val inner_map : t -> (t -> t) -> t
 
 val handle_bs_non_obj_ffi :
+  ?transformed_jsx:bool ->
   External_arg_spec.params ->
   External_ffi_types.return_wrapper ->
   External_ffi_types.external_spec ->
@@ -103,7 +109,7 @@ val global_module : ?dynamic_import:bool -> ident -> t
 
 val const : Lam_constant.t -> t
 
-val apply : t -> t list -> ap_info -> t
+val apply : ?ap_transformed_jsx:bool -> t -> t list -> ap_info -> t
 
 val function_ :
   attr:Lambda.function_attribute ->
diff --git a/compiler/core/lam_bounded_vars.ml b/compiler/core/lam_bounded_vars.ml
index 15ee9cff97..e038e56798 100644
--- a/compiler/core/lam_bounded_vars.ml
+++ b/compiler/core/lam_bounded_vars.ml
@@ -108,10 +108,10 @@ let rewrite (map : _ Hash_ident.t) (lam : Lam.t) : Lam.t =
       (* here it makes sure that global vars are not rebound *)
       Lam.prim ~primitive ~args:(Ext_list.map args aux) loc
     | Lglobal_module _ -> lam
-    | Lapply {ap_func; ap_args; ap_info} ->
+    | Lapply {ap_func; ap_args; ap_info; ap_transformed_jsx} ->
       let fn = aux ap_func in
       let args = Ext_list.map ap_args aux in
-      Lam.apply fn args ap_info
+      Lam.apply ~ap_transformed_jsx fn args ap_info
     | Lswitch
         ( l,
           {
diff --git a/compiler/core/lam_compile.ml b/compiler/core/lam_compile.ml
index ea865bbe6f..58ba342170 100644
--- a/compiler/core/lam_compile.ml
+++ b/compiler/core/lam_compile.ml
@@ -31,12 +31,13 @@ let args_either_function_or_const (args : Lam.t list) =
       | Lfunction _ | Lconst _ -> true
       | _ -> false)
 
-let call_info_of_ap_status (ap_status : Lam.apply_status) : Js_call_info.t =
+let call_info_of_ap_status call_transformed_jsx (ap_status : Lam.apply_status) :
+    Js_call_info.t =
   (* XXX *)
   match ap_status with
-  | App_infer_full -> {arity = Full; call_info = Call_ml}
-  | App_uncurry -> {arity = Full; call_info = Call_na}
-  | App_na -> {arity = NA; call_info = Call_ml}
+  | App_infer_full -> {arity = Full; call_info = Call_ml; call_transformed_jsx}
+  | App_uncurry -> {arity = Full; call_info = Call_na; call_transformed_jsx}
+  | App_na -> {arity = NA; call_info = Call_ml; call_transformed_jsx}
 
 let rec apply_with_arity_aux (fn : J.expression) (arity : int list)
     (args : E.t list) (len : int) : E.t =
@@ -49,7 +50,14 @@ let rec apply_with_arity_aux (fn : J.expression) (arity : int list)
       if len >= x then
         let first_part, continue = Ext_list.split_at args x in
         apply_with_arity_aux
-          (E.call ~info:{arity = Full; call_info = Call_ml} fn first_part)
+          (E.call
+             ~info:
+               {
+                 arity = Full;
+                 call_info = Call_ml;
+                 (* no clue if this is correct *) call_transformed_jsx = false;
+               }
+             fn first_part)
           rest continue (len - x)
       else if
         (* GPR #1423 *)
@@ -63,7 +71,13 @@ let rec apply_with_arity_aux (fn : J.expression) (arity : int list)
           [
             S.return_stmt
               (E.call
-                 ~info:{arity = Full; call_info = Call_ml}
+                 ~info:
+                   {
+                     arity = Full;
+                     call_info = Call_ml;
+                     (* no clue if this is correct *) call_transformed_jsx =
+                       false;
+                   }
                  fn
                  (Ext_list.append args @@ Ext_list.map params E.var));
           ]
@@ -306,7 +320,9 @@ let compile output_prefix =
       let expression =
         match appinfo.ap_info.ap_status with
         | (App_infer_full | App_uncurry) as ap_status ->
-          E.call ~info:(call_info_of_ap_status ap_status) fn args
+          E.call
+            ~info:(call_info_of_ap_status appinfo.ap_transformed_jsx ap_status)
+            fn args
         | App_na -> (
           match ident_info.arity with
           | Submodule _ | Single Arity_na ->
@@ -1439,6 +1455,7 @@ let compile output_prefix =
      ap_func =
        Lapply {ap_func; ap_args; ap_info = {ap_status = App_na; ap_inlined}};
      ap_info = {ap_status = App_na} as outer_ap_info;
+     ap_transformed_jsx;
     } ->
       (* After inlining, we can generate such code, see {!Ari_regress_test}*)
       let ap_info =
@@ -1446,7 +1463,9 @@ let compile output_prefix =
         else {outer_ap_info with ap_inlined}
       in
       compile_lambda lambda_cxt
-        (Lam.apply ap_func (Ext_list.append ap_args appinfo.ap_args) ap_info)
+        (Lam.apply ap_func
+           (Ext_list.append ap_args appinfo.ap_args)
+           ap_info ~ap_transformed_jsx)
     (* External function call: it can not be tailcall in this case*)
     | {
      ap_func =
@@ -1529,7 +1548,9 @@ let compile output_prefix =
         Js_output.output_of_block_and_expression lambda_cxt.continuation
           args_code
           (E.call
-             ~info:(call_info_of_ap_status appinfo.ap_info.ap_status)
+             ~info:
+               (call_info_of_ap_status appinfo.ap_transformed_jsx
+                  appinfo.ap_info.ap_status)
              fn_code args))
   and compile_prim (prim_info : Lam.prim_info)
       (lambda_cxt : Lam_compile_context.t) =
diff --git a/compiler/core/lam_compile_external_call.ml b/compiler/core/lam_compile_external_call.ml
index 6d9056e570..2a5ff0f3f4 100644
--- a/compiler/core/lam_compile_external_call.ml
+++ b/compiler/core/lam_compile_external_call.ml
@@ -267,9 +267,9 @@ let translate_scoped_access scopes obj =
   | [] -> obj
   | x :: xs -> Ext_list.fold_left xs (E.dot obj x) E.dot
 
-let translate_ffi (cxt : Lam_compile_context.t) arg_types
-    (ffi : External_ffi_types.external_spec) (args : J.expression list)
-    ~dynamic_import =
+let translate_ffi ?(transformed_jsx = false) (cxt : Lam_compile_context.t)
+    arg_types (ffi : External_ffi_types.external_spec)
+    (args : J.expression list) ~dynamic_import =
   match ffi with
   | Js_call
       {external_module_name; name; splice : _; scopes; tagged_template = true}
@@ -287,7 +287,15 @@ let translate_ffi (cxt : Lam_compile_context.t) arg_types
     | _ ->
       let args, eff, dynamic = assemble_args_has_splice arg_types args in
       let args = if dynamic then E.variadic_args args else args in
-      add_eff eff (E.call ~info:{arity = Full; call_info = Call_na} fn args))
+      add_eff eff
+        (E.call
+           ~info:
+             {
+               arity = Full;
+               call_info = Call_na;
+               call_transformed_jsx = transformed_jsx;
+             }
+           fn args))
   | Js_call
       {
         external_module_name = module_name;
@@ -302,20 +310,52 @@ let translate_ffi (cxt : Lam_compile_context.t) arg_types
     if splice then
       let args, eff, dynamic = assemble_args_has_splice arg_types args in
       let args = if dynamic then E.variadic_args args else args in
-      add_eff eff (E.call ~info:{arity = Full; call_info = Call_na} fn args)
+      add_eff eff
+        (E.call
+           ~info:
+             {
+               arity = Full;
+               call_info = Call_na;
+               call_transformed_jsx = transformed_jsx;
+             }
+           fn args)
     else
       let args, eff = assemble_args_no_splice arg_types args in
-      add_eff eff @@ E.call ~info:{arity = Full; call_info = Call_na} fn args
+      add_eff eff
+      @@ E.call
+           ~info:
+             {
+               arity = Full;
+               call_info = Call_na;
+               call_transformed_jsx = transformed_jsx;
+             }
+           fn args
   | Js_module_as_fn {external_module_name; splice} ->
     let fn = external_var external_module_name ~dynamic_import in
     if splice then
       let args, eff, dynamic = assemble_args_has_splice arg_types args in
       let args = if dynamic then E.variadic_args args else args in
-      add_eff eff (E.call ~info:{arity = Full; call_info = Call_na} fn args)
+      add_eff eff
+        (E.call
+           ~info:
+             {
+               arity = Full;
+               call_info = Call_na;
+               call_transformed_jsx = transformed_jsx;
+             }
+           fn args)
     else
       let args, eff = assemble_args_no_splice arg_types args in
       (* TODO: fix in rest calling convention *)
-      add_eff eff (E.call ~info:{arity = Full; call_info = Call_na} fn args)
+      add_eff eff
+        (E.call
+           ~info:
+             {
+               arity = Full;
+               call_info = Call_na;
+               call_transformed_jsx = transformed_jsx;
+             }
+           fn args)
   | Js_new {external_module_name = module_name; name = fn; splice; scopes} ->
     (* handle [@@new]*)
     (* This has some side effect, it will
@@ -362,14 +402,24 @@ let translate_ffi (cxt : Lam_compile_context.t) arg_types
         add_eff eff
           (let self = translate_scoped_access js_send_scopes self in
            E.call
-             ~info:{arity = Full; call_info = Call_na}
+             ~info:
+               {
+                 arity = Full;
+                 call_info = Call_na;
+                 call_transformed_jsx = transformed_jsx;
+               }
              (E.dot self name) args)
       else
         let args, eff = assemble_args_no_splice arg_types args in
         add_eff eff
           (let self = translate_scoped_access js_send_scopes self in
            E.call
-             ~info:{arity = Full; call_info = Call_na}
+             ~info:
+               {
+                 arity = Full;
+                 call_info = Call_na;
+                 call_transformed_jsx = transformed_jsx;
+               }
              (E.dot self name) args)
     | _ -> assert false)
   | Js_module_as_var module_name -> external_var module_name ~dynamic_import
@@ -384,7 +434,15 @@ let translate_ffi (cxt : Lam_compile_context.t) arg_types
         ~dynamic_import
     in
     if args = [] then e
-    else E.call ~info:{arity = Full; call_info = Call_na} e args
+    else
+      E.call
+        ~info:
+          {
+            arity = Full;
+            call_info = Call_na;
+            call_transformed_jsx = transformed_jsx;
+          }
+        e args
   | Js_module_as_class module_name ->
     let fn = external_var module_name ~dynamic_import in
     let args, eff = assemble_args_no_splice arg_types args in
diff --git a/compiler/core/lam_compile_external_call.mli b/compiler/core/lam_compile_external_call.mli
index e8c974f10a..29e05c96f9 100644
--- a/compiler/core/lam_compile_external_call.mli
+++ b/compiler/core/lam_compile_external_call.mli
@@ -30,6 +30,7 @@ val ocaml_to_js_eff :
 (** Compile ocaml external function call to JS IR. *)
 
 val translate_ffi :
+  ?transformed_jsx:bool ->
   Lam_compile_context.t ->
   External_arg_spec.params ->
   External_ffi_types.external_spec ->
diff --git a/compiler/core/lam_compile_primitive.ml b/compiler/core/lam_compile_primitive.ml
index aac979d926..ae17cd8077 100644
--- a/compiler/core/lam_compile_primitive.ml
+++ b/compiler/core/lam_compile_primitive.ml
@@ -56,14 +56,14 @@ let get_module_system () =
 
 let import_of_path path =
   E.call
-    ~info:{arity = Full; call_info = Call_na}
+    ~info:{arity = Full; call_info = Call_na; call_transformed_jsx = false}
     (E.js_global "import")
     [E.str path]
 
 let wrap_then import value =
   let arg = Ident.create "m" in
   E.call
-    ~info:{arity = Full; call_info = Call_na}
+    ~info:{arity = Full; call_info = Call_na; call_transformed_jsx = false}
     (E.dot import "then")
     [
       E.ocaml_fun ~return_unit:false ~async:false ~one_unit_arg:false [arg]
@@ -88,7 +88,10 @@ let translate output_prefix loc (cxt : Lam_compile_context.t)
     | _ -> assert false)
   | Pjs_apply -> (
     match args with
-    | fn :: rest -> E.call ~info:{arity = Full; call_info = Call_na} fn rest
+    | fn :: rest ->
+      E.call
+        ~info:{arity = Full; call_info = Call_na; call_transformed_jsx = false}
+        fn rest
     | _ -> assert false)
   | Pnull_to_opt -> (
     match args with
@@ -594,9 +597,9 @@ let translate output_prefix loc (cxt : Lam_compile_context.t)
   (* Lam_compile_external_call.translate loc cxt prim args *)
   (* Test if the argument is a block or an immediate integer *)
   | Pjs_object_create _ -> assert false
-  | Pjs_call {arg_types; ffi; dynamic_import} ->
+  | Pjs_call {arg_types; ffi; dynamic_import; transformed_jsx} ->
     Lam_compile_external_call.translate_ffi cxt arg_types ffi args
-      ~dynamic_import
+      ~dynamic_import ~transformed_jsx
   (* FIXME, this can be removed later *)
   | Pisint -> E.is_type_number (Ext_list.singleton_exn args)
   | Pis_poly_var_block -> E.is_type_object (Ext_list.singleton_exn args)
diff --git a/compiler/core/lam_convert.ml b/compiler/core/lam_convert.ml
index 3f252011ef..9bac6891f4 100644
--- a/compiler/core/lam_convert.ml
+++ b/compiler/core/lam_convert.ml
@@ -348,8 +348,8 @@ let rec rename_optional_parameters map params (body : Lambda.lambda) =
         value_kind,
         id,
         Lifthenelse
-          ( Lprim (p, [Lvar ({name = "*opt*"} as opt)], p_loc),
-            Lprim (p1, [Lvar ({name = "*opt*"} as opt2)], x_loc),
+          ( Lprim (p, [Lvar ({name = "*opt*"} as opt)], p_loc, p_tj),
+            Lprim (p1, [Lvar ({name = "*opt*"} as opt2)], x_loc, x_tj),
             f ),
         rest )
     when Ident.same opt opt2 && List.mem opt params ->
@@ -361,8 +361,8 @@ let rec rename_optional_parameters map params (body : Lambda.lambda) =
           value_kind,
           id,
           Lifthenelse
-            ( Lprim (p, [Lvar new_id], p_loc),
-              Lprim (p1, [Lvar new_id], x_loc),
+            ( Lprim (p, [Lvar new_id], p_loc, p_tj),
+              Lprim (p1, [Lvar new_id], x_loc, x_tj),
               f ),
           rest ) )
   | _ -> (map, body)
@@ -373,8 +373,9 @@ let convert (exports : Set_ident.t) (lam : Lambda.lambda) :
   let exit_map = Hash_int.create 0 in
   let may_depends = Lam_module_ident.Hash_set.create 0 in
 
-  let rec convert_ccall (a_prim : Primitive.description)
-      (args : Lambda.lambda list) loc ~dynamic_import : Lam.t =
+  let rec convert_ccall ?(transformed_jsx = false)
+      (a_prim : Primitive.description) (args : Lambda.lambda list) loc
+      ~dynamic_import : Lam.t =
     let prim_name = a_prim.prim_name in
     match External_ffi_types.from_string a_prim.prim_native_name with
     | Ffi_obj_create labels ->
@@ -387,8 +388,8 @@ let convert (exports : Set_ident.t) (lam : Lambda.lambda) :
         | Param_number i -> Ext_list.init i (fun _ -> External_arg_spec.dummy)
       in
       let args = Ext_list.map args convert_aux in
-      Lam.handle_bs_non_obj_ffi arg_types result_type ffi args loc prim_name
-        ~dynamic_import
+      Lam.handle_bs_non_obj_ffi ~transformed_jsx arg_types result_type ffi args
+        loc prim_name ~dynamic_import
     | Ffi_inline_const i -> Lam.const i
     | Ffi_normal ->
       Location.raise_errorf ~loc
@@ -414,11 +415,19 @@ let convert (exports : Set_ident.t) (lam : Lambda.lambda) :
       let setter = Ext_string.ends_with name Literals.setter_suffix in
       let _ = assert (not setter) in
       prim ~primitive:(Pjs_unsafe_downgrade {name; setter}) ~args loc
-    | Lapply {ap_func = fn; ap_args = args; ap_loc = loc; ap_inlined} ->
+    | Lapply
+        {
+          ap_func = fn;
+          ap_args = args;
+          ap_loc = loc;
+          ap_inlined;
+          ap_transformed_jsx;
+        } ->
       (* we need do this eargly in case [aux fn] add some wrapper *)
       Lam.apply (convert_aux fn)
         (Ext_list.map args convert_aux)
         {ap_loc = loc; ap_inlined; ap_status = App_uncurry}
+        ~ap_transformed_jsx
     | Lfunction {params; body; attr} ->
       let new_map, body =
         rename_optional_parameters Map_ident.empty params body
@@ -439,20 +448,21 @@ let convert (exports : Set_ident.t) (lam : Lambda.lambda) :
       let lam = Lam.letrec bindings body in
       Lam_scc.scc bindings lam body
     (* inlining will affect how mututal recursive behave *)
-    | Lprim (Prevapply, [x; f], outer_loc) | Lprim (Pdirapply, [f; x], outer_loc)
-      ->
+    | Lprim (Prevapply, [x; f], outer_loc, _)
+    | Lprim (Pdirapply, [f; x], outer_loc, _) ->
       convert_pipe f x outer_loc
-    | Lprim (Prevapply, _, _) -> assert false
-    | Lprim (Pdirapply, _, _) -> assert false
-    | Lprim (Pccall a, args, loc) -> convert_ccall a args loc ~dynamic_import
-    | Lprim (Pjs_raw_expr, args, loc) -> (
+    | Lprim (Prevapply, _, _, _) -> assert false
+    | Lprim (Pdirapply, _, _, _) -> assert false
+    | Lprim (Pccall a, args, loc, transformed_jsx) ->
+      convert_ccall ~transformed_jsx a args loc ~dynamic_import
+    | Lprim (Pjs_raw_expr, args, loc, _) -> (
       match args with
       | [Lconst (Const_base (Const_string (code, _)))] ->
         (* js parsing here *)
         let kind = Classify_function.classify code in
         prim ~primitive:(Praw_js_code {code; code_info = Exp kind}) ~args:[] loc
       | _ -> assert false)
-    | Lprim (Pjs_raw_stmt, args, loc) -> (
+    | Lprim (Pjs_raw_stmt, args, loc, _) -> (
       match args with
       | [Lconst (Const_base (Const_string (code, _)))] ->
         let kind = Classify_function.classify_stmt code in
@@ -460,7 +470,7 @@ let convert (exports : Set_ident.t) (lam : Lambda.lambda) :
           ~primitive:(Praw_js_code {code; code_info = Stmt kind})
           ~args:[] loc
       | _ -> assert false)
-    | Lprim (Pgetglobal id, args, _) ->
+    | Lprim (Pgetglobal id, args, _, _) ->
       let args = Ext_list.map args convert_aux in
       if Ident.is_predef_exn id then
         Lam.const (Const_string {s = id.name; unicode = false})
@@ -468,10 +478,10 @@ let convert (exports : Set_ident.t) (lam : Lambda.lambda) :
         may_depend may_depends (Lam_module_ident.of_ml ~dynamic_import id);
         assert (args = []);
         Lam.global_module ~dynamic_import id)
-    | Lprim (Pimport, args, loc) ->
+    | Lprim (Pimport, args, loc, _) ->
       let args = Ext_list.map args (convert_aux ~dynamic_import:true) in
       lam_prim ~primitive:Pimport ~args loc
-    | Lprim (primitive, args, loc) ->
+    | Lprim (primitive, args, loc, tj) ->
       let args = Ext_list.map args (convert_aux ~dynamic_import) in
       lam_prim ~primitive ~args loc
     | Lswitch (e, s, _loc) -> convert_switch e s
@@ -571,8 +581,8 @@ let convert (exports : Set_ident.t) (lam : Lambda.lambda) :
       when Ext_list.for_all2_no_exn inner_args params lam_is_var
            && Ext_list.length_larger_than_n inner_args args 1 ->
       Lam.prim ~primitive ~args:(Ext_list.append_one args x) outer_loc
-    | Lapply {ap_func; ap_args; ap_info} ->
-      Lam.apply ap_func
+    | Lapply {ap_func; ap_args; ap_info; ap_transformed_jsx} ->
+      Lam.apply ~ap_transformed_jsx ap_func
         (Ext_list.append_one ap_args x)
         {
           ap_loc = outer_loc;
diff --git a/compiler/core/lam_pass_alpha_conversion.ml b/compiler/core/lam_pass_alpha_conversion.ml
index 3beadbeb0e..1d80ae16ed 100644
--- a/compiler/core/lam_pass_alpha_conversion.ml
+++ b/compiler/core/lam_pass_alpha_conversion.ml
@@ -23,14 +23,17 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)
 
 let alpha_conversion (meta : Lam_stats.t) (lam : Lam.t) : Lam.t =
-  let rec populate_apply_info (args_arity : int list) (len : int) (fn : Lam.t)
-      (args : Lam.t list) ap_info : Lam.t =
+  let rec populate_apply_info ?(ap_transformed_jsx = false)
+      (args_arity : int list) (len : int) (fn : Lam.t) (args : Lam.t list)
+      ap_info : Lam.t =
     match args_arity with
-    | 0 :: _ | [] -> Lam.apply (simpl fn) (Ext_list.map args simpl) ap_info
+    | 0 :: _ | [] ->
+      Lam.apply (simpl fn) (Ext_list.map args simpl) ap_info ~ap_transformed_jsx
     | x :: _ ->
       if x = len then
         Lam.apply (simpl fn) (Ext_list.map args simpl)
           {ap_info with ap_status = App_infer_full}
+          ~ap_transformed_jsx
       else if x > len then
         let fn = simpl fn in
         let args = Ext_list.map args simpl in
@@ -39,7 +42,7 @@ let alpha_conversion (meta : Lam_stats.t) (lam : Lam.t) : Lam.t =
           fn args
       else
         let first, rest = Ext_list.split_at args x in
-        Lam.apply
+        Lam.apply ~ap_transformed_jsx
           (Lam.apply (simpl fn) (Ext_list.map first simpl)
              {ap_info with ap_status = App_infer_full})
           (Ext_list.map rest simpl) ap_info
@@ -48,13 +51,14 @@ let alpha_conversion (meta : Lam_stats.t) (lam : Lam.t) : Lam.t =
     match lam with
     | Lconst _ -> lam
     | Lvar _ -> lam
-    | Lapply {ap_func; ap_args; ap_info} ->
+    | Lapply {ap_func; ap_args; ap_info; ap_transformed_jsx} ->
       (* detect functor application *)
       let args_arity =
         Lam_arity.extract_arity (Lam_arity_analysis.get_arity meta ap_func)
       in
       let len = List.length ap_args in
-      populate_apply_info args_arity len ap_func ap_args ap_info
+      populate_apply_info ~ap_transformed_jsx args_arity len ap_func ap_args
+        ap_info
     | Llet (str, v, l1, l2) -> Lam.let_ str v (simpl l1) (simpl l2)
     | Lletrec (bindings, body) ->
       let bindings = Ext_list.map_snd bindings simpl in
diff --git a/compiler/core/lam_pass_deep_flatten.ml b/compiler/core/lam_pass_deep_flatten.ml
index c55aeec841..0eddcb1a9d 100644
--- a/compiler/core/lam_pass_deep_flatten.ml
+++ b/compiler/core/lam_pass_deep_flatten.ml
@@ -224,8 +224,8 @@ let deep_flatten (lam : Lam.t) : Lam.t =
     (*           can we switch to the tupled backend? *\) *)
     (*   when  List.length params = List.length args -> *)
     (*       aux (beta_reduce params body args) *)
-    | Lapply {ap_func = l1; ap_args = ll; ap_info} ->
-      Lam.apply (aux l1) (Ext_list.map ll aux) ap_info
+    | Lapply {ap_func = l1; ap_args = ll; ap_info; ap_transformed_jsx} ->
+      Lam.apply (aux l1) (Ext_list.map ll aux) ap_info ~ap_transformed_jsx
     (* This kind of simple optimizations should be done each time
        and as early as possible *)
     | Lglobal_module _ -> lam
diff --git a/compiler/core/lam_pass_eliminate_ref.ml b/compiler/core/lam_pass_eliminate_ref.ml
index 4a251c1877..eb54fb2067 100644
--- a/compiler/core/lam_pass_eliminate_ref.ml
+++ b/compiler/core/lam_pass_eliminate_ref.ml
@@ -52,8 +52,10 @@ let rec eliminate_ref id (lam : Lam.t) =
     Lam.assign id
       (Lam.prim ~primitive:(Poffsetint delta) ~args:[Lam.var id] loc)
   | Lconst _ -> lam
-  | Lapply {ap_func = e1; ap_args = el; ap_info} ->
-    Lam.apply (eliminate_ref id e1) (Ext_list.map el (eliminate_ref id)) ap_info
+  | Lapply {ap_func = e1; ap_args = el; ap_info; ap_transformed_jsx} ->
+    Lam.apply ~ap_transformed_jsx (eliminate_ref id e1)
+      (Ext_list.map el (eliminate_ref id))
+      ap_info
   | Llet (str, v, e1, e2) ->
     Lam.let_ str v (eliminate_ref id e1) (eliminate_ref id e2)
   | Lletrec (idel, e2) ->
diff --git a/compiler/core/lam_pass_exits.ml b/compiler/core/lam_pass_exits.ml
index ceba4af6e5..2eb6295699 100644
--- a/compiler/core/lam_pass_exits.ml
+++ b/compiler/core/lam_pass_exits.ml
@@ -199,8 +199,10 @@ let subst_helper (subst : subst_tbl) (query : int -> int) (lam : Lam.t) : Lam.t
             Lam.let_ Strict y l r)
       | None -> Lam.staticraise i ls)
     | Lvar _ | Lconst _ -> lam
-    | Lapply {ap_func; ap_args; ap_info} ->
-      Lam.apply (simplif ap_func) (Ext_list.map ap_args simplif) ap_info
+    | Lapply {ap_func; ap_args; ap_info; ap_transformed_jsx} ->
+      Lam.apply (simplif ap_func)
+        (Ext_list.map ap_args simplif)
+        ap_info ~ap_transformed_jsx
     | Lfunction {arity; params; body; attr} ->
       Lam.function_ ~arity ~params ~body:(simplif body) ~attr
     | Llet (kind, v, l1, l2) -> Lam.let_ kind v (simplif l1) (simplif l2)
diff --git a/compiler/core/lam_pass_lets_dce.ml b/compiler/core/lam_pass_lets_dce.ml
index ca6e32bc7c..04ab02d4bc 100644
--- a/compiler/core/lam_pass_lets_dce.ml
+++ b/compiler/core/lam_pass_lets_dce.ml
@@ -144,8 +144,9 @@ let lets_helper (count_var : Ident.t -> Lam_pass_count.used_info) lam : Lam.t =
       (*   *\) *)
       (*   when  Ext_list.same_length params  args -> *)
       (*   simplif (Lam_beta_reduce.beta_reduce params body args) *)
-    | Lapply {ap_func = l1; ap_args = ll; ap_info} ->
+    | Lapply {ap_func = l1; ap_args = ll; ap_info; ap_transformed_jsx} ->
       Lam.apply (simplif l1) (Ext_list.map ll simplif) ap_info
+        ~ap_transformed_jsx
     | Lfunction {arity; params; body; attr} ->
       Lam.function_ ~arity ~params ~body:(simplif body) ~attr
     | Lconst _ -> lam
diff --git a/compiler/core/lam_pass_remove_alias.ml b/compiler/core/lam_pass_remove_alias.ml
index 065ea65edf..67472564fe 100644
--- a/compiler/core/lam_pass_remove_alias.ml
+++ b/compiler/core/lam_pass_remove_alias.ml
@@ -140,19 +140,23 @@ let simplify_alias (meta : Lam_stats.t) (lam : Lam.t) : Lam.t =
                     | _ -> true)
              && Lam_analysis.lfunction_can_be_inlined lfunction ->
         simpl (Lam_beta_reduce.propagate_beta_reduce meta params body args)
-      | _ -> Lam.apply (simpl l1) (Ext_list.map args simpl) ap_info)
+      | _ ->
+        Lam.apply (simpl l1) (Ext_list.map args simpl) ap_info
+          ?ap_transformed_jsx:None)
     (* Function inlining interact with other optimizations...
 
        - parameter attributes
        - scope issues
        - code bloat
     *)
-    | Lapply {ap_func = Lvar v as fn; ap_args; ap_info} -> (
+    | Lapply {ap_func = Lvar v as fn; ap_args; ap_info; ap_transformed_jsx} -> (
       (* Check info for always inlining *)
 
       (* Ext_log.dwarn __LOC__ "%s/%d" v.name v.stamp;     *)
       let ap_args = Ext_list.map ap_args simpl in
-      let[@local] normal () = Lam.apply (simpl fn) ap_args ap_info in
+      let[@local] normal () =
+        Lam.apply (simpl fn) ap_args ap_info ~ap_transformed_jsx
+      in
       match Hash_ident.find_opt meta.ident_tbl v with
       | Some
           (FunctionId
@@ -221,8 +225,8 @@ let simplify_alias (meta : Lam_stats.t) (lam : Lam.t) : Lam.t =
     (*   *\) *)
     (*   when  Ext_list.same_length params args -> *)
     (*   simpl (Lam_beta_reduce.propogate_beta_reduce meta params body args) *)
-    | Lapply {ap_func = l1; ap_args = ll; ap_info} ->
-      Lam.apply (simpl l1) (Ext_list.map ll simpl) ap_info
+    | Lapply {ap_func = l1; ap_args = ll; ap_info; ap_transformed_jsx} ->
+      Lam.apply (simpl l1) (Ext_list.map ll simpl) ap_info ~ap_transformed_jsx
     | Lfunction {arity; params; body; attr} ->
       Lam.function_ ~arity ~params ~body:(simpl body) ~attr
     | Lswitch
diff --git a/compiler/core/lam_primitive.ml b/compiler/core/lam_primitive.ml
index e28c652cd9..f07b5aa024 100644
--- a/compiler/core/lam_primitive.ml
+++ b/compiler/core/lam_primitive.ml
@@ -46,6 +46,7 @@ type t =
       arg_types: External_arg_spec.params;
       ffi: External_ffi_types.external_spec;
       dynamic_import: bool;
+      transformed_jsx: bool;
     }
   | Pjs_object_create of External_arg_spec.obj_params
   (* Exceptions *)
@@ -250,7 +251,7 @@ let eq_primitive_approx (lhs : t) (rhs : t) =
     | Pmakeblock (i1, info1, flag1) ->
       i0 = i1 && flag0 = flag1 && eq_tag_info info0 info1
     | _ -> false)
-  | Pjs_call {prim_name; arg_types; ffi; dynamic_import} -> (
+  | Pjs_call {prim_name; arg_types; ffi; dynamic_import; _} -> (
     match rhs with
     | Pjs_call rhs ->
       prim_name = rhs.prim_name && arg_types = rhs.arg_types && ffi = rhs.ffi
diff --git a/compiler/core/lam_primitive.mli b/compiler/core/lam_primitive.mli
index 460ef392c4..19b10cf964 100644
--- a/compiler/core/lam_primitive.mli
+++ b/compiler/core/lam_primitive.mli
@@ -42,6 +42,7 @@ type t =
       arg_types: External_arg_spec.params;
       ffi: External_ffi_types.external_spec;
       dynamic_import: bool;
+      transformed_jsx: bool;
     }
   | Pjs_object_create of External_arg_spec.obj_params
   | Praise
diff --git a/compiler/core/lam_util.ml b/compiler/core/lam_util.ml
index 7ea859f6be..f85cdc0f41 100644
--- a/compiler/core/lam_util.ml
+++ b/compiler/core/lam_util.ml
@@ -66,7 +66,7 @@ let refine_let
   (*     let v= subst_lambda (Map_ident.singleton param arg ) l in *)
   (*     Ext_log.err "@[substitution << @]@."; *)
   (* v *)
-  | _, _, Lapply {ap_func=fn; ap_args = [Lvar w]; ap_info} when
+  | _, _, Lapply {ap_func=fn; ap_args = [Lvar w]; ap_info; ap_transformed_jsx} when
       Ident.same w param &&
       (not (Lam_hit.hit_variable param fn ))
     -> 
@@ -79,7 +79,7 @@ let refine_let
        ]}
         #1667 make sure body does not hit k 
     *)
-    Lam.apply fn [arg] ap_info
+    Lam.apply fn [arg] ap_info ~ap_transformed_jsx
   | (Strict | StrictOpt ),
     ( Lvar _    | Lconst  _ | 
       Lprim {primitive = Pfield (_ , Fld_module _) ;  
diff --git a/compiler/core/polyvar_pattern_match.ml b/compiler/core/polyvar_pattern_match.ml
index fea0b53f1d..0fd5bd585d 100644
--- a/compiler/core/polyvar_pattern_match.ml
+++ b/compiler/core/polyvar_pattern_match.ml
@@ -65,7 +65,8 @@ let or_list (arg : lam) (hash_names : (int * string) list) =
       Lprim
         ( Pintcomp Ceq,
           [arg; Lconst (Const_pointer (hash, Pt_variant {name}))],
-          Location.none )
+          Location.none,
+          false )
     in
     Ext_list.fold_left rest init (fun acc (hash, name) ->
         Lambda.Lprim
@@ -75,9 +76,11 @@ let or_list (arg : lam) (hash_names : (int * string) list) =
               Lprim
                 ( Pintcomp Ceq,
                   [arg; Lconst (Const_pointer (hash, Pt_variant {name}))],
-                  Location.none );
+                  Location.none,
+                  false );
             ],
-            Location.none ))
+            Location.none,
+            false ))
   | _ -> assert false
 
 let make_test_sequence_variant_constant (fail : lam option) (arg : lam)
@@ -111,5 +114,5 @@ let call_switcher_variant_constr (loc : Location.t) (fail : lam option)
     ( Alias,
       Pgenval,
       v,
-      Lprim (Pfield (0, Fld_poly_var_tag), [arg], loc),
+      Lprim (Pfield (0, Fld_poly_var_tag), [arg], loc, false),
       call_switcher_variant_constant loc fail (Lvar v) int_lambda_list names )
diff --git a/compiler/frontend/ast_compatible.ml b/compiler/frontend/ast_compatible.ml
index 04a1be4f4a..0610abb015 100644
--- a/compiler/frontend/ast_compatible.ml
+++ b/compiler/frontend/ast_compatible.ml
@@ -44,6 +44,7 @@ let apply_simple ?(loc = default_loc) ?(attrs = []) (fn : expression)
           funct = fn;
           args = Ext_list.map args (fun x -> (Asttypes.Nolabel, x));
           partial = false;
+          transformed_jsx = false;
         };
   }
 
@@ -52,7 +53,13 @@ let app1 ?(loc = default_loc) ?(attrs = []) fn arg1 : expression =
     pexp_loc = loc;
     pexp_attributes = attrs;
     pexp_desc =
-      Pexp_apply {funct = fn; args = [(Nolabel, arg1)]; partial = false};
+      Pexp_apply
+        {
+          funct = fn;
+          args = [(Nolabel, arg1)];
+          partial = false;
+          transformed_jsx = false;
+        };
   }
 
 let app2 ?(loc = default_loc) ?(attrs = []) fn arg1 arg2 : expression =
@@ -61,7 +68,12 @@ let app2 ?(loc = default_loc) ?(attrs = []) fn arg1 arg2 : expression =
     pexp_attributes = attrs;
     pexp_desc =
       Pexp_apply
-        {funct = fn; args = [(Nolabel, arg1); (Nolabel, arg2)]; partial = false};
+        {
+          funct = fn;
+          args = [(Nolabel, arg1); (Nolabel, arg2)];
+          partial = false;
+          transformed_jsx = false;
+        };
   }
 
 let app3 ?(loc = default_loc) ?(attrs = []) fn arg1 arg2 arg3 : expression =
@@ -74,6 +86,7 @@ let app3 ?(loc = default_loc) ?(attrs = []) fn arg1 arg2 arg3 : expression =
           funct = fn;
           args = [(Nolabel, arg1); (Nolabel, arg2); (Nolabel, arg3)];
           partial = false;
+          transformed_jsx = false;
         };
   }
 
@@ -121,6 +134,7 @@ let apply_labels ?(loc = default_loc) ?(attrs = []) fn
             Ext_list.map args (fun (l, a) ->
                 (Asttypes.Labelled {txt = l; loc = Location.none}, a));
           partial = false;
+          transformed_jsx = false;
         };
   }
 
diff --git a/compiler/frontend/ast_exp_apply.ml b/compiler/frontend/ast_exp_apply.ml
index fb5b500db9..afffea4e3c 100644
--- a/compiler/frontend/ast_exp_apply.ml
+++ b/compiler/frontend/ast_exp_apply.ml
@@ -88,11 +88,12 @@ let app_exp_mapper (e : exp) (self : Bs_ast_mapper.mapper) : exp =
       {f with pexp_desc = Pexp_variant (label, Some a); pexp_loc = e.pexp_loc}
     | Pexp_construct (ctor, None) ->
       {f with pexp_desc = Pexp_construct (ctor, Some a); pexp_loc = e.pexp_loc}
-    | Pexp_apply {funct = fn1; args; partial} ->
+    | Pexp_apply {funct = fn1; args; partial; transformed_jsx} ->
       Bs_ast_invariant.warn_discarded_unused_attributes fn1.pexp_attributes;
       {
         pexp_desc =
-          Pexp_apply {funct = fn1; args = (Nolabel, a) :: args; partial};
+          Pexp_apply
+            {funct = fn1; args = (Nolabel, a) :: args; partial; transformed_jsx};
         pexp_loc = e.pexp_loc;
         pexp_attributes = e.pexp_attributes @ f.pexp_attributes;
       }
@@ -108,7 +109,7 @@ let app_exp_mapper (e : exp) (self : Bs_ast_mapper.mapper) : exp =
                          fn with
                          pexp_desc = Pexp_construct (ctor, Some bounded_obj_arg);
                        }
-                     | Pexp_apply {funct = fn; args} ->
+                     | Pexp_apply {funct = fn; args; transformed_jsx} ->
                        Bs_ast_invariant.warn_discarded_unused_attributes
                          fn.pexp_attributes;
                        {
@@ -118,6 +119,7 @@ let app_exp_mapper (e : exp) (self : Bs_ast_mapper.mapper) : exp =
                                funct = fn;
                                args = (Nolabel, bounded_obj_arg) :: args;
                                partial = false;
+                               transformed_jsx;
                              };
                          pexp_attributes = [];
                          pexp_loc = fn.pexp_loc;
diff --git a/compiler/frontend/ast_uncurry_gen.ml b/compiler/frontend/ast_uncurry_gen.ml
index 70e4e2d550..9e0a43fe37 100644
--- a/compiler/frontend/ast_uncurry_gen.ml
+++ b/compiler/frontend/ast_uncurry_gen.ml
@@ -75,4 +75,5 @@ let to_method_callback loc (self : Bs_ast_mapper.mapper) label
                  [Typ.any ~loc ()]) );
         ];
       partial = false;
+      transformed_jsx = false;
     }
diff --git a/compiler/frontend/bs_ast_mapper.ml b/compiler/frontend/bs_ast_mapper.ml
index 72799db97b..cf684bdd30 100644
--- a/compiler/frontend/bs_ast_mapper.ml
+++ b/compiler/frontend/bs_ast_mapper.ml
@@ -330,8 +330,8 @@ module E = struct
       fun_ ~loc ~attrs ~arity ~async lab
         (map_opt (sub.expr sub) def)
         (sub.pat sub p) (sub.expr sub e)
-    | Pexp_apply {funct = e; args = l; partial} ->
-      apply ~loc ~attrs ~partial (sub.expr sub e)
+    | Pexp_apply {funct = e; args = l; partial; transformed_jsx} ->
+      apply ~loc ~attrs ~partial ~transformed_jsx (sub.expr sub e)
         (List.map (map_snd (sub.expr sub)) l)
     | Pexp_match (e, pel) ->
       match_ ~loc ~attrs (sub.expr sub e) (sub.cases sub pel)
diff --git a/compiler/ml/ast_helper.ml b/compiler/ml/ast_helper.ml
index d4de7ff0e9..121bea0c1f 100644
--- a/compiler/ml/ast_helper.ml
+++ b/compiler/ml/ast_helper.ml
@@ -154,8 +154,9 @@ module Exp = struct
   let fun_ ?loc ?attrs ?(async = false) ~arity a b c d =
     mk ?loc ?attrs
       (Pexp_fun {arg_label = a; default = b; lhs = c; rhs = d; arity; async})
-  let apply ?loc ?attrs ?(partial = false) funct args =
-    mk ?loc ?attrs (Pexp_apply {funct; args; partial})
+  let apply ?loc ?attrs ?(partial = false) ?(transformed_jsx = false) funct args
+      =
+    mk ?loc ?attrs (Pexp_apply {funct; args; partial; transformed_jsx})
   let match_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_match (a, b))
   let try_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_try (a, b))
   let tuple ?loc ?attrs a = mk ?loc ?attrs (Pexp_tuple a)
diff --git a/compiler/ml/ast_helper.mli b/compiler/ml/ast_helper.mli
index 10677c31b2..bbcf4471a3 100644
--- a/compiler/ml/ast_helper.mli
+++ b/compiler/ml/ast_helper.mli
@@ -149,6 +149,7 @@ module Exp : sig
     ?loc:loc ->
     ?attrs:attrs ->
     ?partial:bool ->
+    ?transformed_jsx:bool ->
     expression ->
     (arg_label * expression) list ->
     expression
diff --git a/compiler/ml/ast_mapper.ml b/compiler/ml/ast_mapper.ml
index 992d1a9816..67c757d685 100644
--- a/compiler/ml/ast_mapper.ml
+++ b/compiler/ml/ast_mapper.ml
@@ -293,8 +293,8 @@ module E = struct
       fun_ ~loc ~attrs ~arity ~async lab
         (map_opt (sub.expr sub) def)
         (sub.pat sub p) (sub.expr sub e)
-    | Pexp_apply {funct = e; args = l; partial} ->
-      apply ~loc ~attrs ~partial (sub.expr sub e)
+    | Pexp_apply {funct = e; args = l; partial; transformed_jsx} ->
+      apply ~loc ~attrs ~partial ~transformed_jsx (sub.expr sub e)
         (List.map (map_snd (sub.expr sub)) l)
     | Pexp_match (e, pel) ->
       match_ ~loc ~attrs (sub.expr sub e) (sub.cases sub pel)
diff --git a/compiler/ml/lambda.ml b/compiler/ml/lambda.ml
index 26aa8a8c74..0692f0aedb 100644
--- a/compiler/ml/lambda.ml
+++ b/compiler/ml/lambda.ml
@@ -357,7 +357,7 @@ type lambda =
   | Lfunction of lfunction
   | Llet of let_kind * value_kind * Ident.t * lambda * lambda
   | Lletrec of (Ident.t * lambda) list * lambda
-  | Lprim of primitive * lambda list * Location.t
+  | Lprim of primitive * lambda list * Location.t * bool
   | Lswitch of lambda * lambda_switch * Location.t
   | Lstringswitch of
       lambda * (string * lambda) list * lambda option * Location.t
@@ -383,6 +383,7 @@ and lambda_apply = {
   ap_args: lambda list;
   ap_loc: Location.t;
   ap_inlined: inline_attribute;
+  ap_transformed_jsx: bool;
 }
 
 and lambda_switch = {
@@ -461,7 +462,7 @@ let make_key e =
       let ex = tr_rec env ex in
       let y = make_key x in
       Llet (str, k, y, ex, tr_rec (Ident.add x (Lvar y) env) e)
-    | Lprim (p, es, _) -> Lprim (p, tr_recs env es, Location.none)
+    | Lprim (p, es, _, tj) -> Lprim (p, tr_recs env es, Location.none, tj)
     | Lswitch (e, sw, loc) -> Lswitch (tr_rec env e, tr_sw env sw, loc)
     | Lstringswitch (e, sw, d, _) ->
       Lstringswitch
@@ -519,7 +520,7 @@ let iter f = function
   | Lletrec (decl, body) ->
     f body;
     List.iter (fun (_id, exp) -> f exp) decl
-  | Lprim (_p, args, _loc) -> List.iter f args
+  | Lprim (_p, args, _loc, _tj) -> List.iter f args
   | Lswitch (arg, sw, _) ->
     f arg;
     List.iter (fun (_key, case) -> f case) sw.sw_consts;
@@ -617,13 +618,14 @@ let rec patch_guarded patch = function
 
 let rec transl_normal_path = function
   | Path.Pident id ->
-    if Ident.global id then Lprim (Pgetglobal id, [], Location.none)
+    if Ident.global id then Lprim (Pgetglobal id, [], Location.none, false)
     else Lvar id
   | Pdot (p, s, pos) ->
     Lprim
       ( Pfield (pos, Fld_module {name = s}),
         [transl_normal_path p],
-        Location.none )
+        Location.none,
+        false )
   | Papply _ -> assert false
 
 (* Translation of identifiers *)
@@ -657,7 +659,7 @@ let subst_lambda s lam =
       Lfunction {params; body = subst body; attr; loc}
     | Llet (str, k, id, arg, body) -> Llet (str, k, id, subst arg, subst body)
     | Lletrec (decl, body) -> Lletrec (List.map subst_decl decl, subst body)
-    | Lprim (p, args, loc) -> Lprim (p, List.map subst args, loc)
+    | Lprim (p, args, loc, tj) -> Lprim (p, List.map subst args, loc, tj)
     | Lswitch (arg, sw, loc) ->
       Lswitch
         ( subst arg,
diff --git a/compiler/ml/lambda.mli b/compiler/ml/lambda.mli
index 9e1c9b9d7c..12ff51c086 100644
--- a/compiler/ml/lambda.mli
+++ b/compiler/ml/lambda.mli
@@ -324,7 +324,7 @@ type lambda =
   | Lfunction of lfunction
   | Llet of let_kind * value_kind * Ident.t * lambda * lambda
   | Lletrec of (Ident.t * lambda) list * lambda
-  | Lprim of primitive * lambda list * Location.t
+  | Lprim of primitive * lambda list * Location.t * bool
   | Lswitch of lambda * lambda_switch * Location.t
   (* switch on strings, clauses are sorted by string order,
      strings are pairwise distinct *)
@@ -352,6 +352,7 @@ and lambda_apply = {
   ap_args: lambda list;
   ap_loc: Location.t;
   ap_inlined: inline_attribute; (* specified with the [@inlined] attribute *)
+  ap_transformed_jsx: bool;
 }
 
 and lambda_switch = {
diff --git a/compiler/ml/matching.ml b/compiler/ml/matching.ml
index fd90f38535..dde5d74a62 100644
--- a/compiler/ml/matching.ml
+++ b/compiler/ml/matching.ml
@@ -1194,7 +1194,7 @@ let make_field_args ~fld_info loc binding_kind arg first_pos last_pos argl =
   let rec make_args pos =
     if pos > last_pos then argl
     else
-      (Lprim (Pfield (pos, fld_info), [arg], loc), binding_kind)
+      (Lprim (Pfield (pos, fld_info), [arg], loc, false), binding_kind)
       :: make_args (pos + 1)
   in
   make_args first_pos
@@ -1277,7 +1277,7 @@ let make_constr_matching p def ctx = function
               Pval_from_option_not_nest
             | _ -> Pval_from_option
           in
-          (Lprim (from_option, [arg], p.pat_loc), Alias) :: argl
+          (Lprim (from_option, [arg], p.pat_loc, false), Alias) :: argl
         | Cstr_constant _ | Cstr_block _ ->
           make_field_args p.pat_loc Alias arg 0 (cstr.cstr_arity - 1) argl
             ~fld_info:(if cstr.cstr_name = "::" then Fld_cons else Fld_variant)
@@ -1336,7 +1336,8 @@ let make_variant_matching_nonconst p lab def ctx = function
         {
           cases = [];
           args =
-            (Lprim (Pfield (1, Fld_poly_var_content), [arg], p.pat_loc), Alias)
+            ( Lprim (Pfield (1, Fld_poly_var_content), [arg], p.pat_loc, false),
+              Alias )
             :: argl;
           default = def;
         };
@@ -1426,8 +1427,9 @@ let get_mod_field modname field =
        in
        Lprim
          ( Pfield (p, Fld_module {name = field}),
-           [Lprim (Pgetglobal mod_ident, [], Location.none)],
-           Location.none )
+           [Lprim (Pgetglobal mod_ident, [], Location.none, false)],
+           Location.none,
+           false )
      with Not_found -> fatal_error ("Module " ^ modname ^ " unavailable."))
 
 let code_force = get_mod_field Primitive_modules.lazy_ "force"
@@ -1449,6 +1451,7 @@ let inline_lazy_force arg loc =
       ap_inlined = Default_inline;
       ap_args = [arg];
       ap_loc = loc;
+      ap_transformed_jsx = false;
     }
 let make_lazy_matching def = function
   | [] -> fatal_error "Matching.make_lazy_matching"
@@ -1483,7 +1486,7 @@ let make_tuple_matching loc arity def = function
     let rec make_args pos =
       if pos >= arity then argl
       else
-        (Lprim (Pfield (pos, Fld_tuple), [arg], loc), Alias)
+        (Lprim (Pfield (pos, Fld_tuple), [arg], loc, false), Alias)
         :: make_args (pos + 1)
     in
     {
@@ -1532,16 +1535,21 @@ let make_record_matching loc all_labels def = function
           match lbl.lbl_repres with
           | Record_float_unused -> assert false
           | Record_regular ->
-            Lprim (Pfield (lbl.lbl_pos, Lambda.fld_record lbl), [arg], loc)
+            Lprim
+              (Pfield (lbl.lbl_pos, Lambda.fld_record lbl), [arg], loc, false)
           | Record_inlined _ ->
             Lprim
-              (Pfield (lbl.lbl_pos, Lambda.fld_record_inline lbl), [arg], loc)
+              ( Pfield (lbl.lbl_pos, Lambda.fld_record_inline lbl),
+                [arg],
+                loc,
+                false )
           | Record_unboxed _ -> arg
           | Record_extension ->
             Lprim
               ( Pfield (lbl.lbl_pos + 1, Lambda.fld_record_extension lbl),
                 [arg],
-                loc )
+                loc,
+                false )
         in
         let str =
           match lbl.lbl_mut with
@@ -1586,7 +1594,10 @@ let make_array_matching p def ctx = function
       if pos >= len then argl
       else
         ( Lprim
-            (Parrayrefu, [arg; Lconst (Const_base (Const_int pos))], p.pat_loc),
+            ( Parrayrefu,
+              [arg; Lconst (Const_base (Const_int pos))],
+              p.pat_loc,
+              false ),
           StrictOpt )
         :: make_args (pos + 1)
     in
@@ -1638,7 +1649,8 @@ let make_string_test_sequence loc arg sw d =
       List.fold_right
         (fun (s, lam) k ->
           Lifthenelse
-            ( Lprim (Pstringcomp Cneq, [arg; Lconst (Const_immstring s)], loc),
+            ( Lprim
+                (Pstringcomp Cneq, [arg; Lconst (Const_immstring s)], loc, false),
               k,
               lam ))
         sw d)
@@ -1656,9 +1668,9 @@ let zero_lam = Lconst (Const_base (Const_int 0))
 
 let tree_way_test loc arg lt eq gt =
   Lifthenelse
-    ( Lprim (Pintcomp Clt, [arg; zero_lam], loc),
+    ( Lprim (Pintcomp Clt, [arg; zero_lam], loc, false),
       lt,
-      Lifthenelse (Lprim (Pintcomp Clt, [zero_lam; arg], loc), gt, eq) )
+      Lifthenelse (Lprim (Pintcomp Clt, [zero_lam; arg], loc, false), gt, eq) )
 
 (* Dichotomic tree *)
 
@@ -1669,7 +1681,7 @@ let rec do_make_string_test_tree loc arg sw delta d =
   else
     let lt, (s, act), gt = split len sw in
     bind_sw
-      (Lprim (Pstringcomp Ceq, [arg; Lconst (Const_immstring s)], loc))
+      (Lprim (Pstringcomp Ceq, [arg; Lconst (Const_immstring s)], loc, false))
       (fun r ->
         tree_way_test loc r
           (do_make_string_test_tree loc arg lt delta d)
@@ -1756,7 +1768,7 @@ let rec do_tests_fail loc fail tst arg = function
   | [] -> fail
   | (c, act) :: rem ->
     Lifthenelse
-      ( Lprim (tst, [arg; Lconst (Const_base c)], loc),
+      ( Lprim (tst, [arg; Lconst (Const_base c)], loc, false),
         do_tests_fail loc fail tst arg rem,
         act )
 
@@ -1765,7 +1777,7 @@ let rec do_tests_nofail loc tst arg = function
   | [(_, act)] -> act
   | (c, act) :: rem ->
     Lifthenelse
-      ( Lprim (tst, [arg; Lconst (Const_base c)], loc),
+      ( Lprim (tst, [arg; Lconst (Const_base c)], loc, false),
         do_tests_nofail loc tst arg rem,
         act )
 
@@ -1785,7 +1797,8 @@ let make_test_sequence loc fail tst lt_tst arg const_lambda_list =
       cut (List.length const_lambda_list / 2) const_lambda_list
     in
     Lifthenelse
-      ( Lprim (lt_tst, [arg; Lconst (Const_base (fst (List.hd list2)))], loc),
+      ( Lprim
+          (lt_tst, [arg; Lconst (Const_base (fst (List.hd list2)))], loc, false),
         make_test_sequence list1,
         make_test_sequence list2 )
   in
@@ -1803,11 +1816,11 @@ module SArg = struct
 
   type act = Lambda.lambda
 
-  let make_prim p args = Lprim (p, args, Location.none)
+  let make_prim p args = Lprim (p, args, Location.none, false)
   let make_offset arg n =
     match n with
     | 0 -> arg
-    | _ -> Lprim (Poffsetint n, [arg], Location.none)
+    | _ -> Lprim (Poffsetint n, [arg], Location.none, false)
 
   let bind arg body =
     let newvar, newarg =
@@ -1819,8 +1832,8 @@ module SArg = struct
     in
     bind Alias newvar arg (body newarg)
   let make_const i = Lconst (Const_base (Const_int i))
-  let make_isout h arg = Lprim (Pisout, [h; arg], Location.none)
-  let make_isin h arg = Lprim (Pnot, [make_isout h arg], Location.none)
+  let make_isout h arg = Lprim (Pisout, [h; arg], Location.none, false)
+  let make_isin h arg = Lprim (Pnot, [make_isout h arg], Location.none, false)
   let make_if cond ifso ifnot = Lifthenelse (cond, ifso, ifnot)
   let make_switch loc arg cases acts ~offset sw_names =
     let l = ref [] in
@@ -2215,7 +2228,9 @@ let combine_constructor sw_names loc arg ex_pat cstr partial ctx def
             (fun (path, act) rem ->
               let ext = transl_extension_path ex_pat.pat_env path in
               Lifthenelse
-                (Lprim (Pextension_slot_eq, [Lvar tag; ext], loc), act, rem))
+                ( Lprim (Pextension_slot_eq, [Lvar tag; ext], loc, false),
+                  act,
+                  rem ))
             extension_cases default
         in
         Llet (Alias, Pgenval, tag, arg, tests)
@@ -2245,9 +2260,13 @@ let combine_constructor sw_names loc arg ex_pat cstr partial ctx def
              case *)
           let arg =
             if Datarepr.constructor_has_optional_shape cstr then
-              Lprim (Pis_not_none, [arg], loc)
+              Lprim (Pis_not_none, [arg], loc, false)
             else
-              Lprim (Pjscomp Cneq, [arg; Lconst (Const_base (Const_int 0))], loc)
+              Lprim
+                ( Pjscomp Cneq,
+                  [arg; Lconst (Const_base (Const_int 0))],
+                  loc,
+                  false )
           in
           Lifthenelse (arg, act2, act1)
         | 2, 0, [(i1, act1); (_, act2)], []
@@ -2271,7 +2290,7 @@ let combine_constructor sw_names loc arg ex_pat cstr partial ctx def
           match act0 with
           | Some act when false (* relies on tag being an int *) ->
             Lifthenelse
-              ( Lprim (Pisint, [arg], loc),
+              ( Lprim (Pisint, [arg], loc, false),
                 call_switcher loc fail_opt arg 0 (n - 1) consts sw_names,
                 act )
           (* Emit a switch, as bytecode implements this sophisticated instruction *)
@@ -2310,7 +2329,7 @@ let call_switcher_variant_constr loc fail arg int_lambda_list names =
     ( Alias,
       Pgenval,
       v,
-      Lprim (Pfield (0, Fld_poly_var_tag), [arg], loc),
+      Lprim (Pfield (0, Fld_poly_var_tag), [arg], loc, false),
       call_switcher loc fail (Lvar v) min_int max_int
         (List.map (fun (a, (_, c)) -> (a, c)) int_lambda_list)
         names )
@@ -2356,7 +2375,7 @@ let combine_variant names loc row arg partial ctx def
       row.row_fields
   else num_constr := max_int;
   let test_int_or_block arg if_int if_block =
-    Lifthenelse (Lprim (Pis_poly_var_block, [arg], loc), if_block, if_int)
+    Lifthenelse (Lprim (Pis_poly_var_block, [arg], loc, false), if_block, if_int)
   in
   let sig_complete = List.length tag_lambda_list = !num_constr
   and one_action = same_actions tag_lambda_list in
@@ -2406,7 +2425,7 @@ let combine_array names loc arg partial ctx def (len_lambda_list, total1, _pats)
     let switch =
       call_switcher loc fail (Lvar newvar) 0 max_int len_lambda_list names
     in
-    bind Alias newvar (Lprim (Parraylength, [arg], loc)) switch
+    bind Alias newvar (Lprim (Parraylength, [arg], loc, false)) switch
   in
   (lambda1, jumps_union local_jumps total1)
 
@@ -2487,7 +2506,7 @@ let compile_test compile_fun partial divide combine ctx to_match =
 let rec approx_present v = function
   | Lconst _ -> false
   | Lstaticraise (_, args) -> List.exists (fun lam -> approx_present v lam) args
-  | Lprim (_, args, _) -> List.exists (fun lam -> approx_present v lam) args
+  | Lprim (_, args, _, _) -> List.exists (fun lam -> approx_present v lam) args
   | Llet (Alias, _k, _, l1, l2) -> approx_present v l1 || approx_present v l2
   | Lvar vv -> Ident.same v vv
   | _ -> true
@@ -2834,9 +2853,11 @@ let partial_function loc () =
                        Const_base (Const_int char);
                      ] ));
             ],
-            loc );
+            loc,
+            false );
       ],
-      loc )
+      loc,
+      false )
 
 let for_function loc repr param pat_act_list partial =
   compile_matching repr (partial_function loc) param pat_act_list partial
@@ -2844,7 +2865,7 @@ let for_function loc repr param pat_act_list partial =
 (* In the following two cases, exhaustiveness info is not available! *)
 let for_trywith param pat_act_list =
   compile_matching None
-    (fun () -> Lprim (Praise Raise_reraise, [param], Location.none))
+    (fun () -> Lprim (Praise Raise_reraise, [param], Location.none, false))
     param pat_act_list Partial
 
 let simple_for_let loc param pat body =
@@ -3011,14 +3032,14 @@ let do_for_multiple_match loc paraml pat_act_list partial =
       ( raise_num,
         {
           cases = List.map (fun (pat, act) -> ([pat], act)) pat_act_list;
-          args = [(Lprim (Pmakeblock Blk_tuple, paraml, loc), Strict)];
+          args = [(Lprim (Pmakeblock Blk_tuple, paraml, loc, false), Strict)];
           default = [([[omega]], raise_num)];
         } )
     | _ ->
       ( -1,
         {
           cases = List.map (fun (pat, act) -> ([pat], act)) pat_act_list;
-          args = [(Lprim (Pmakeblock Blk_tuple, paraml, loc), Strict)];
+          args = [(Lprim (Pmakeblock Blk_tuple, paraml, loc, false), Strict)];
           default = [];
         } )
   in
diff --git a/compiler/ml/parsetree.ml b/compiler/ml/parsetree.ml
index 5c47210630..5184b9f674 100644
--- a/compiler/ml/parsetree.ml
+++ b/compiler/ml/parsetree.ml
@@ -244,6 +244,7 @@ and expression_desc =
       funct: expression;
       args: (arg_label * expression) list;
       partial: bool;
+      transformed_jsx: bool;
     }
     (* E0 ~l1:E1 ... ~ln:En
        li can be empty (non labeled argument) or start with '?'
diff --git a/compiler/ml/printast.ml b/compiler/ml/printast.ml
index 380939b15b..48429c34d0 100644
--- a/compiler/ml/printast.ml
+++ b/compiler/ml/printast.ml
@@ -251,11 +251,12 @@ and expression i ppf x =
     option i expression ppf eo;
     pattern i ppf p;
     expression i ppf e
-  | Pexp_apply {funct = e; args = l; partial} ->
+  | Pexp_apply {funct = e; args = l; partial; transformed_jsx} ->
     line i ppf "Pexp_apply\n";
     if partial then line i ppf "partial\n";
     expression i ppf e;
-    list i label_x_expression ppf l
+    list i label_x_expression ppf l;
+    line i ppf "transformed_jsx: %b\n" transformed_jsx
   | Pexp_match (e, l) ->
     line i ppf "Pexp_match\n";
     expression i ppf e;
diff --git a/compiler/ml/printlambda.ml b/compiler/ml/printlambda.ml
index f0ad4698bb..e069e7173b 100644
--- a/compiler/ml/printlambda.ml
+++ b/compiler/ml/printlambda.ml
@@ -319,7 +319,7 @@ let rec lam ppf = function
     in
     fprintf ppf "@[<2>(letrec@ (@[<hv 1>%a@])@ %a)@]" bindings id_arg_list lam
       body
-  | Lprim (prim, largs, _) ->
+  | Lprim (prim, largs, _, _) ->
     let lams ppf largs = List.iter (fun l -> fprintf ppf "@ %a" lam l) largs in
     fprintf ppf "@[<2>(%a%a)@]" primitive prim lams largs
   | Lswitch (larg, sw, _loc) ->
diff --git a/compiler/ml/tast_mapper.ml b/compiler/ml/tast_mapper.ml
index 8064d65990..c2e33e7b4f 100644
--- a/compiler/ml/tast_mapper.ml
+++ b/compiler/ml/tast_mapper.ml
@@ -199,12 +199,13 @@ let expr sub x =
     | Texp_function {arg_label; arity; param; case; partial; async} ->
       Texp_function
         {arg_label; arity; param; case = sub.case sub case; partial; async}
-    | Texp_apply {funct = exp; args = list; partial} ->
+    | Texp_apply {funct = exp; args = list; partial; transformed_jsx} ->
       Texp_apply
         {
           funct = sub.expr sub exp;
           args = List.map (tuple2 id (opt (sub.expr sub))) list;
           partial;
+          transformed_jsx;
         }
     | Texp_match (exp, cases, exn_cases, p) ->
       Texp_match
diff --git a/compiler/ml/transl_recmodule.ml b/compiler/ml/transl_recmodule.ml
index 17aa511aa2..8a6acad180 100644
--- a/compiler/ml/transl_recmodule.ml
+++ b/compiler/ml/transl_recmodule.ml
@@ -151,7 +151,7 @@ let eval_rec_bindings_aux (bindings : binding list) (cont : t) : t =
         ( Strict,
           Pgenval,
           id,
-          Lprim (Pinit_mod, [loc; shape], Location.none),
+          Lprim (Pinit_mod, [loc; shape], Location.none, false),
           bind_inits rem acc )
   in
   let rec bind_strict args acc =
@@ -167,7 +167,7 @@ let eval_rec_bindings_aux (bindings : binding list) (cont : t) : t =
     | (_id, None, _rhs) :: rem -> patch_forwards rem
     | (id, Some (_loc, shape), rhs) :: rem ->
       Lsequence
-        ( Lprim (Pupdate_mod, [shape; Lvar id; rhs], Location.none),
+        ( Lprim (Pupdate_mod, [shape; Lvar id; rhs], Location.none, false),
           patch_forwards rem )
   in
   bind_inits bindings (bind_strict bindings (patch_forwards bindings))
@@ -178,7 +178,7 @@ let eval_rec_bindings_aux (bindings : binding list) (cont : t) : t =
 *)
 let rec is_function_or_const_block (lam : Lambda.lambda) acc =
   match lam with
-  | Lprim (Pmakeblock _, args, _) ->
+  | Lprim (Pmakeblock _, args, _, _) ->
     Ext_list.for_all args (fun x ->
         match x with
         | Lvar id -> Set_ident.mem acc id
diff --git a/compiler/ml/translattribute.ml b/compiler/ml/translattribute.ml
index ed63ecbdf1..800d630d0c 100644
--- a/compiler/ml/translattribute.ml
+++ b/compiler/ml/translattribute.ml
@@ -76,8 +76,8 @@ let rec add_inline_attribute (expr : Lambda.lambda) loc attributes =
       Location.prerr_warning loc (Warnings.Duplicated_attribute "inline"));
     let attr = {attr with inline} in
     Lfunction {funct with attr}
-  | Lprim (((Pjs_fn_make _ | Pjs_fn_make_unit) as p), [e], l), _ ->
-    Lambda.Lprim (p, [add_inline_attribute e loc attributes], l)
+  | Lprim (((Pjs_fn_make _ | Pjs_fn_make_unit) as p), [e], l, tj), _ ->
+    Lambda.Lprim (p, [add_inline_attribute e loc attributes], l, tj)
   | expr, Always_inline ->
     Location.prerr_warning loc (Warnings.Misplaced_attribute "inline1");
     expr
diff --git a/compiler/ml/translcore.ml b/compiler/ml/translcore.ml
index 4cdeb34aa5..7c9a50731e 100644
--- a/compiler/ml/translcore.ml
+++ b/compiler/ml/translcore.ml
@@ -44,7 +44,7 @@ let transl_extension_constructor env path ext =
   in
   let loc = ext.ext_loc in
   match ext.ext_kind with
-  | Text_decl _ -> Lprim (Pcreate_extension name, [], loc)
+  | Text_decl _ -> Lprim (Pcreate_extension name, [], loc, false)
   | Text_rebind (path, _lid) -> transl_extension_path ~loc env path
 
 (* Translation of primitives *)
@@ -460,7 +460,7 @@ let transl_primitive loc p env ty =
           params = [param];
           attr = default_function_attribute;
           loc;
-          body = Lprim (Pmakeblock Blk_tuple, [lam; Lvar param], loc);
+          body = Lprim (Pmakeblock Blk_tuple, [lam; Lvar param], loc, false);
         }
     | _ -> assert false)
   | _ ->
@@ -471,7 +471,8 @@ let transl_primitive loc p env ty =
         :: make_params (n - 1) total
     in
     let prim_arity = p.prim_arity in
-    if p.prim_from_constructor || prim_arity = 0 then Lprim (prim, [], loc)
+    if p.prim_from_constructor || prim_arity = 0 then
+      Lprim (prim, [], loc, false)
     else
       let params =
         if prim_arity = 1 then [Ident.create "prim"]
@@ -482,7 +483,7 @@ let transl_primitive loc p env ty =
           params;
           attr = default_function_attribute;
           loc;
-          body = Lprim (prim, List.map (fun id -> Lvar id) params, loc);
+          body = Lprim (prim, List.map (fun id -> Lvar id) params, loc, false);
         }
 
 let transl_primitive_application loc prim env ty args =
@@ -629,9 +630,11 @@ let assert_failed exp =
                        Const_base (Const_int char);
                      ] ));
             ],
-            exp.exp_loc );
+            exp.exp_loc,
+            false );
       ],
-      exp.exp_loc )
+      exp.exp_loc,
+      false )
 
 let rec cut n l =
   if n = 0 then ([], l)
@@ -700,7 +703,8 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
       Lprim
         ( prim (* could be replaced with Opaque in the future except arity 0*),
           [lambda],
-          loc )
+          loc,
+          false )
     | None -> lambda)
   | Texp_apply
       {
@@ -710,6 +714,7 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
             exp_type = prim_type;
           } as funct;
         args = oargs;
+        transformed_jsx;
       }
     when List.length oargs >= p.prim_arity
          && List.for_all (fun (_, arg) -> arg <> None) oargs -> (
@@ -720,7 +725,7 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
         let inlined, _ =
           Translattribute.get_and_remove_inlined_attribute funct
         in
-        transl_apply ~inlined f args' e.exp_loc
+        transl_apply ~inlined ~transformed_jsx f args' e.exp_loc
     in
     let args =
       List.map
@@ -741,16 +746,16 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
         | Raise_regular, Lvar id when Hashtbl.mem try_ids id -> Raise_reraise
         | _ -> k
       in
-      wrap (Lprim (Praise k, [targ], e.exp_loc))
+      wrap (Lprim (Praise k, [targ], e.exp_loc, transformed_jsx))
     | Ploc kind, [] -> lam_of_loc kind e.exp_loc
     | Ploc kind, [arg1] ->
       let lam = lam_of_loc kind arg1.exp_loc in
-      Lprim (Pmakeblock Blk_tuple, lam :: argl, e.exp_loc)
+      Lprim (Pmakeblock Blk_tuple, lam :: argl, e.exp_loc, transformed_jsx)
     | Ploc _, _ -> assert false
     | _, _ -> (
       match (prim, argl) with
-      | _ -> wrap (Lprim (prim, argl, e.exp_loc))))
-  | Texp_apply {funct; args = oargs; partial} ->
+      | _ -> wrap (Lprim (prim, argl, e.exp_loc, transformed_jsx))))
+  | Texp_apply {funct; args = oargs; partial; transformed_jsx} ->
     let inlined, funct =
       Translattribute.get_and_remove_inlined_attribute funct
     in
@@ -766,8 +771,8 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
         | None -> None
       else None
     in
-    transl_apply ~inlined ~uncurried_partial_application (transl_exp funct)
-      oargs e.exp_loc
+    transl_apply ~inlined ~uncurried_partial_application ~transformed_jsx
+      (transl_exp funct) oargs e.exp_loc
   | Texp_match (arg, pat_expr_list, exn_pat_expr_list, partial) ->
     transl_match e arg pat_expr_list exn_pat_expr_list partial
   | Texp_try (body, pat_expr_list) ->
@@ -779,7 +784,7 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
   | Texp_tuple el -> (
     let ll = transl_list el in
     try Lconst (Const_block (Blk_tuple, List.map extract_constant ll))
-    with Not_constant -> Lprim (Pmakeblock Blk_tuple, ll, e.exp_loc))
+    with Not_constant -> Lprim (Pmakeblock Blk_tuple, ll, e.exp_loc, false))
   | Texp_construct ({txt = Lident "false"}, _, []) -> Lconst Const_false
   | Texp_construct ({txt = Lident "true"}, _, []) -> Lconst Const_true
   | Texp_construct (lid, cstr, args) -> (
@@ -834,12 +839,13 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
               }
         in
         try Lconst (Const_block (tag_info, List.map extract_constant ll))
-        with Not_constant -> Lprim (Pmakeblock tag_info, ll, e.exp_loc))
+        with Not_constant -> Lprim (Pmakeblock tag_info, ll, e.exp_loc, false))
       | Cstr_extension path ->
         Lprim
           ( Pmakeblock Blk_extension,
             transl_extension_path e.exp_env path :: ll,
-            e.exp_loc ))
+            e.exp_loc,
+            false ))
   | Texp_extension_constructor (_, path) -> transl_extension_path e.exp_env path
   | Texp_variant (l, arg) -> (
     let tag = Btype.hash_variant l in
@@ -856,7 +862,8 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
         Lprim
           ( Pmakeblock tag_info,
             [Lconst (Const_base (Const_int tag)); lam],
-            e.exp_loc )))
+            e.exp_loc,
+            false )))
   | Texp_record {fields; representation; extended_expression} ->
     transl_record e.exp_loc e.exp_env fields representation extended_expression
   | Texp_field (arg, _, lbl) -> (
@@ -864,16 +871,21 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
     match lbl.lbl_repres with
     | Record_float_unused -> assert false
     | Record_regular ->
-      Lprim (Pfield (lbl.lbl_pos, Lambda.fld_record lbl), [targ], e.exp_loc)
+      Lprim
+        (Pfield (lbl.lbl_pos, Lambda.fld_record lbl), [targ], e.exp_loc, false)
     | Record_inlined _ ->
       Lprim
-        (Pfield (lbl.lbl_pos, Lambda.fld_record_inline lbl), [targ], e.exp_loc)
+        ( Pfield (lbl.lbl_pos, Lambda.fld_record_inline lbl),
+          [targ],
+          e.exp_loc,
+          false )
     | Record_unboxed _ -> targ
     | Record_extension ->
       Lprim
         ( Pfield (lbl.lbl_pos + 1, Lambda.fld_record_extension lbl),
           [targ],
-          e.exp_loc ))
+          e.exp_loc,
+          false ))
   | Texp_setfield (arg, _, lbl, newval) ->
     let access =
       match lbl.lbl_repres with
@@ -885,10 +897,10 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
       | Record_extension ->
         Psetfield (lbl.lbl_pos + 1, Lambda.fld_record_extension_set lbl)
     in
-    Lprim (access, [transl_exp arg; transl_exp newval], e.exp_loc)
+    Lprim (access, [transl_exp arg; transl_exp newval], e.exp_loc, false)
   | Texp_array expr_list ->
     let ll = transl_list expr_list in
-    Lprim (Pmakearray Mutable, ll, e.exp_loc)
+    Lprim (Pmakearray Mutable, ll, e.exp_loc, false)
   | Texp_ifthenelse (cond, ifso, Some ifnot) ->
     Lifthenelse (transl_exp cond, transl_exp ifso, transl_exp ifnot)
   | Texp_ifthenelse (cond, ifso, None) ->
@@ -922,7 +934,7 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
     (* when e needs no computation (constants, identifiers, ...), we
        optimize the translation just as Lazy.lazy_from_val would
        do *)
-    Lprim (Pmakeblock Blk_lazy_general, [transl_exp e], e.exp_loc)
+    Lprim (Pmakeblock Blk_lazy_general, [transl_exp e], e.exp_loc, false)
 
 and transl_list expr_list = List.map transl_exp expr_list
 
@@ -948,9 +960,17 @@ and transl_case_try {c_lhs; c_guard; c_rhs} =
 and transl_cases_try cases = List.map transl_case_try cases
 
 and transl_apply ?(inlined = Default_inline)
-    ?(uncurried_partial_application = None) lam sargs loc =
+    ?(uncurried_partial_application = None) ?(transformed_jsx = false) lam sargs
+    loc =
   let lapply ap_func ap_args =
-    Lapply {ap_loc = loc; ap_func; ap_args; ap_inlined = inlined}
+    Lapply
+      {
+        ap_loc = loc;
+        ap_func;
+        ap_args;
+        ap_inlined = inlined;
+        ap_transformed_jsx = transformed_jsx;
+      }
   in
   let rec build_apply lam args = function
     | (None, optional) :: l ->
@@ -1008,7 +1028,14 @@ and transl_apply ?(inlined = Default_inline)
     let extra_args = Ext_list.map extra_ids (fun id -> Lvar id) in
     let ap_args = args @ extra_args in
     let l0 =
-      Lapply {ap_func = lam; ap_args; ap_inlined = inlined; ap_loc = loc}
+      Lapply
+        {
+          ap_func = lam;
+          ap_args;
+          ap_inlined = inlined;
+          ap_loc = loc;
+          ap_transformed_jsx = transformed_jsx;
+        }
     in
     Lfunction
       {
@@ -1097,7 +1124,8 @@ and transl_record loc env fields repres opt_init_expr =
         ( Pjs_fn_make arity,
           (* could be replaced with Opaque in the future except arity 0*)
           [lambda],
-          loc )
+          loc,
+          false )
     else lambda
   | _ -> (
     let size = Array.length fields in
@@ -1134,7 +1162,7 @@ and transl_record loc env fields repres opt_init_expr =
                 | Record_extension ->
                   Pfield (i + 1, Lambda.fld_record_extension lbl)
               in
-              Lprim (access, [Lvar init_id], loc)
+              Lprim (access, [Lvar init_id], loc, false)
             | Overridden (_lid, expr) -> transl_exp expr)
           fields
       in
@@ -1167,7 +1195,7 @@ and transl_record loc env fields repres opt_init_expr =
         with Not_constant -> (
           match repres with
           | Record_regular ->
-            Lprim (Pmakeblock (Lambda.blk_record fields mut), ll, loc)
+            Lprim (Pmakeblock (Lambda.blk_record fields mut), ll, loc, false)
           | Record_float_unused -> assert false
           | Record_inlined {tag; name; num_nonconsts; attrs} ->
             Lprim
@@ -1175,7 +1203,8 @@ and transl_record loc env fields repres opt_init_expr =
                   (Lambda.blk_record_inlined fields name num_nonconsts ~tag
                      ~attrs mut),
                 ll,
-                loc )
+                loc,
+                false )
           | Record_unboxed _ -> (
             match ll with
             | [v] -> v
@@ -1189,7 +1218,10 @@ and transl_record loc env fields repres opt_init_expr =
             in
             let slot = transl_extension_path env path in
             Lprim
-              (Pmakeblock (Lambda.blk_record_ext fields mut), slot :: ll, loc))
+              ( Pmakeblock (Lambda.blk_record_ext fields mut),
+                slot :: ll,
+                loc,
+                false ))
       in
       match opt_init_expr with
       | None -> lam
@@ -1214,7 +1246,8 @@ and transl_record loc env fields repres opt_init_expr =
             | Record_extension ->
               Psetfield (lbl.lbl_pos + 1, Lambda.fld_record_extension_set lbl)
           in
-          Lsequence (Lprim (upd, [Lvar copy_id; transl_exp expr], loc), cont)
+          Lsequence
+            (Lprim (upd, [Lvar copy_id; transl_exp expr], loc, false), cont)
       in
       match opt_init_expr with
       | None -> assert false
@@ -1223,7 +1256,7 @@ and transl_record loc env fields repres opt_init_expr =
           ( Strict,
             Pgenval,
             copy_id,
-            Lprim (Pduprecord, [transl_exp init_expr], loc),
+            Lprim (Pduprecord, [transl_exp init_expr], loc, false),
             Array.fold_left update_field (Lvar copy_id) fields ))
 
 and transl_match e arg pat_expr_list exn_pat_expr_list partial =
diff --git a/compiler/ml/translmod.ml b/compiler/ml/translmod.ml
index f815a536c0..0b06c7b890 100644
--- a/compiler/ml/translmod.ml
+++ b/compiler/ml/translmod.ml
@@ -64,15 +64,17 @@ let rec apply_coercion loc strict (restr : Typedtree.module_coercion) arg =
   | Tcoerce_structure (pos_cc_list, id_pos_list, runtime_fields) ->
     Lambda.name_lambda strict arg (fun id ->
         let get_field_name name pos =
-          Lambda.Lprim (Pfield (pos, Fld_module {name}), [Lvar id], loc)
+          Lambda.Lprim (Pfield (pos, Fld_module {name}), [Lvar id], loc, false)
         in
         let lam =
           Lambda.Lprim
             ( Pmakeblock (Blk_module runtime_fields),
               Ext_list.map2 pos_cc_list runtime_fields (fun (pos, cc) name ->
                   apply_coercion loc Alias cc
-                    (Lprim (Pfield (pos, Fld_module {name}), [Lvar id], loc))),
-              loc )
+                    (Lprim
+                       (Pfield (pos, Fld_module {name}), [Lvar id], loc, false))),
+              loc,
+              false )
         in
         wrap_id_pos_list loc id_pos_list get_field_name lam)
   | Tcoerce_functor (cc_arg, cc_res) ->
@@ -100,6 +102,7 @@ and apply_coercion_result loc strict funct param arg cc_res =
                    ap_func = Lvar id;
                    ap_args = [arg];
                    ap_inlined = Default_inline;
+                   ap_transformed_jsx = false;
                  });
         })
 
@@ -276,6 +279,7 @@ and transl_module cc rootpath mexp =
              ap_func = transl_module Tcoerce_none None funct;
              ap_args = [transl_module ccarg None arg];
              ap_inlined = inlined_attribute;
+             ap_transformed_jsx = false;
            })
     | Tmod_constraint (arg, _, _, ccarg) ->
       transl_module (compose_coercions cc ccarg) rootpath arg
@@ -304,7 +308,8 @@ and transl_structure loc fields cc rootpath final_env = function
               (if is_top_root_path then Blk_module_export !export_identifiers
                else Blk_module (List.rev_map (fun id -> id.Ident.name) fields)),
             block_fields,
-            loc ),
+            loc,
+            false ),
         List.length fields )
     | Tcoerce_structure (pos_cc_list, id_pos_list, runtime_fields) ->
       (* Do not ignore id_pos_list ! *)
@@ -340,7 +345,8 @@ and transl_structure loc fields cc rootpath final_env = function
               (if is_top_root_path then Blk_module_export !export_identifiers
                else Blk_module runtime_fields),
             result,
-            loc )
+            loc,
+            false )
       and id_pos_list =
         Ext_list.filter id_pos_list (fun (id, _, _) ->
             not (Lambda.IdentSet.mem id ids))
@@ -432,7 +438,8 @@ and transl_structure loc fields cc rootpath final_env = function
                 Lprim
                   ( Pfield (pos, Fld_module {name = Ident.name id}),
                     [Lvar mid],
-                    incl.incl_loc ),
+                    incl.incl_loc,
+                    false ),
                 body ),
             size )
       in
diff --git a/compiler/ml/typecore.ml b/compiler/ml/typecore.ml
index d1e593607f..a7ac76a341 100644
--- a/compiler/ml/typecore.ml
+++ b/compiler/ml/typecore.ml
@@ -2401,7 +2401,7 @@ and type_expect_ ?type_clash_context ?in_function ?(recarg = Rejected) env sexp
     type_function ?in_function ~arity ~async loc sexp.pexp_attributes env
       ty_expected l
       [Ast_helper.Exp.case spat sbody]
-  | Pexp_apply {funct = sfunct; args = sargs; partial} ->
+  | Pexp_apply {funct = sfunct; args = sargs; partial; transformed_jsx} ->
     assert (sargs <> []);
     begin_def ();
     (* one more level for non-returning functions *)
@@ -2423,7 +2423,7 @@ and type_expect_ ?type_clash_context ?in_function ?(recarg = Rejected) env sexp
     let mk_apply funct args =
       rue
         {
-          exp_desc = Texp_apply {funct; args; partial};
+          exp_desc = Texp_apply {funct; args; partial; transformed_jsx};
           exp_loc = loc;
           exp_extra = [];
           exp_type = ty_res;
diff --git a/compiler/ml/typedtree.ml b/compiler/ml/typedtree.ml
index 626950caec..f9769ee13b 100644
--- a/compiler/ml/typedtree.ml
+++ b/compiler/ml/typedtree.ml
@@ -87,6 +87,7 @@ and expression_desc =
       funct: expression;
       args: (Noloc.arg_label * expression option) list;
       partial: bool;
+      transformed_jsx: bool;
     }
   | Texp_match of expression * case list * case list * partial
   | Texp_try of expression * case list
diff --git a/compiler/ml/typedtree.mli b/compiler/ml/typedtree.mli
index 96da873af0..f3368c9539 100644
--- a/compiler/ml/typedtree.mli
+++ b/compiler/ml/typedtree.mli
@@ -150,6 +150,7 @@ and expression_desc =
       funct: expression;
       args: (Noloc.arg_label * expression option) list;
       partial: bool;
+      transformed_jsx: bool;
     }
       (** E0 ~l1:E1 ... ~ln:En
 
diff --git a/compiler/syntax/src/jsx_v4.ml b/compiler/syntax/src/jsx_v4.ml
index febc245f21..89bb301f2d 100644
--- a/compiler/syntax/src/jsx_v4.ml
+++ b/compiler/syntax/src/jsx_v4.ml
@@ -1208,7 +1208,7 @@ let append_children_prop (config : Jsx_common.jsx_config) mapper
         Exp.apply
           (Exp.ident
              {txt = Ldot (element_binding, "someElement"); loc = Location.none})
-          [(Nolabel, child)]
+          [(Nolabel, mapper.expr mapper child)]
     in
     let is_optional =
       match component_description with
@@ -1277,7 +1277,7 @@ let mk_react_jsx (config : Jsx_common.jsx_config) mapper loc attrs
         [key_prop; (nolabel, unit_expr ~loc:Location.none)] )
   in
   let args = [(nolabel, elementTag); (nolabel, props_record)] @ key_and_unit in
-  Exp.apply ~loc ~attrs jsx_expr args
+  Exp.apply ~loc ~attrs ~transformed_jsx:true jsx_expr args
 
 (* In most situations, the component name is the make function from a module. 
     However, if the name contains a lowercase letter, it means it probably an external component.
diff --git a/compiler/syntax/src/res_core.ml b/compiler/syntax/src/res_core.ml
index 03ed02f450..0078dcabc1 100644
--- a/compiler/syntax/src/res_core.ml
+++ b/compiler/syntax/src/res_core.ml
@@ -2188,12 +2188,18 @@ and parse_binary_expr ?(context = OrdinaryExpr) ?a p prec =
       let loc = mk_loc a.Parsetree.pexp_loc.loc_start b.pexp_loc.loc_end in
       let expr =
         match (token, b.pexp_desc) with
-        | BarGreater, Pexp_apply {funct = fun_expr; args; partial} ->
+        | ( BarGreater,
+            Pexp_apply {funct = fun_expr; args; partial; transformed_jsx} ) ->
           {
             b with
             pexp_desc =
               Pexp_apply
-                {funct = fun_expr; args = args @ [(Nolabel, a)]; partial};
+                {
+                  funct = fun_expr;
+                  args = args @ [(Nolabel, a)];
+                  partial;
+                  transformed_jsx;
+                };
           }
         | BarGreater, _ -> Ast_helper.Exp.apply ~loc b [(Nolabel, a)]
         | _ ->
diff --git a/compiler/syntax/src/res_parsetree_viewer.ml b/compiler/syntax/src/res_parsetree_viewer.ml
index 5305bd3fc2..8abb4155f9 100644
--- a/compiler/syntax/src/res_parsetree_viewer.ml
+++ b/compiler/syntax/src/res_parsetree_viewer.ml
@@ -142,7 +142,13 @@ let rewrite_underscore_apply expr =
     {
       e with
       pexp_desc =
-        Pexp_apply {funct = call_expr; args = new_args; partial = false};
+        Pexp_apply
+          {
+            funct = call_expr;
+            args = new_args;
+            partial = false;
+            transformed_jsx = false;
+          };
     }
   | _ -> expr