diff --git a/compiler/driver.ml b/compiler/driver.ml
index edf985ef..08f6eef1 100644
--- a/compiler/driver.ml
+++ b/compiler/driver.ml
@@ -244,19 +244,19 @@ module Passes = struct
     let avoid_exceptions = avoid_exceptions || closure_conversion in
     (* --closure-conversion implies --avoid-exceptions *)
     let prg =
-      match avoid_exceptions, options.trace, typed with
-      | true, true, _ ->
-        Message.error
-          "Option --avoid-exceptions is not compatible with option --trace"
-      | true, _, Untyped _ ->
+      if avoid_exceptions && options.trace then
+        Message.warning
+          "It is discouraged to use option @{<yellow>--avoid-exceptions@} if you@ also@ need@ @{<yellow>--trace@},@ the@ resulting@ trace@ may@ be@ unreliable@ at@ the@ moment.";
+      match avoid_exceptions, typed with
+      | true, Untyped _ ->
         Lcalc.From_dcalc.translate_program_without_exceptions prg
-      | true, _, Typed _ ->
+      | true, Typed _ ->
         Lcalc.From_dcalc.translate_program_without_exceptions prg
-      | false, _, Typed _ ->
+      | false, Typed _ ->
         Lcalc.From_dcalc.translate_program_with_exceptions prg
-      | false, _, Untyped _ ->
+      | false, Untyped _ ->
         Lcalc.From_dcalc.translate_program_with_exceptions prg
-      | _, _, Custom _ -> invalid_arg "Driver.Passes.lcalc"
+      | _, Custom _ -> invalid_arg "Driver.Passes.lcalc"
     in
     let prg =
       if optimize then begin
diff --git a/compiler/plugins/api_web.ml b/compiler/plugins/api_web.ml
index b080a83c..63cf61fc 100644
--- a/compiler/plugins/api_web.ml
+++ b/compiler/plugins/api_web.ml
@@ -74,8 +74,7 @@ module To_jsoo = struct
       (* Tuples are encoded as an javascript polymorphic array. *)
       Format.fprintf fmt "Js.Unsafe.any_js_array Js.t "
     | TOption t ->
-      Format.fprintf fmt "@[<hov 2>(%a)@] %a" format_typ_with_parens t
-        format_enum_name Expr.option_enum
+      Format.fprintf fmt "@[<hov 2>(%a)@] Js.opt" format_typ_with_parens t
     | TDefault t -> format_typ fmt t
     | TEnum e -> Format.fprintf fmt "%a Js.t" format_enum_name e
     | TArray t1 ->
@@ -116,7 +115,8 @@ module To_jsoo = struct
         elts
     | TOption t ->
       Format.fprintf fmt
-        "(function Eoption.ENone -> Js.null | Eoption.ESome x -> %a x)"
+        "(function Eoption.ENone () -> Js.null | Eoption.ESome x -> Js.some \
+         (%a x))"
         format_to_js t
     | TAny -> Format.fprintf fmt "Js.Unsafe.inject"
     | TArrow _ | TClosureEnv -> ()