diff -uNr ppx_variants_conv-113.33.00/_oasis ppx_variants_conv-113.33.00+4.03/_oasis
--- ppx_variants_conv-113.33.00/_oasis	2016-03-09 16:44:55.000000000 +0100
+++ ppx_variants_conv-113.33.00+4.03/_oasis	2016-03-22 15:13:51.000000000 +0100
@@ -1,8 +1,8 @@
 OASISFormat:      0.4
-OCamlVersion:     >= 4.02.3
+OCamlVersion:     >= 4.03.0
 FindlibVersion:   >= 1.3.2
 Name:             ppx_variants_conv
-Version:          113.33.00
+Version:          113.33.00+4.03
 Synopsis:         Generation of accessor and iteration functions for ocaml variant types
 Authors:          Jane Street Group, LLC <opensource@janestreet.com>
 Copyrights:       (C) 2015-2016 Jane Street Group LLC <opensource@janestreet.com>
diff -uNr ppx_variants_conv-113.33.00/opam ppx_variants_conv-113.33.00+4.03/opam
--- ppx_variants_conv-113.33.00/opam	2016-03-18 12:08:01.000000000 +0100
+++ ppx_variants_conv-113.33.00+4.03/opam	2016-03-22 17:51:38.000000000 +0100
@@ -18,4 +18,4 @@
   "ppx_type_conv"
   "variantslib"
 ]
-available: [ ocaml-version >= "4.02.3" ]
+available: [ ocaml-version >= "4.03.0" ]
diff -uNr ppx_variants_conv-113.33.00/src/ppx_variants_conv.ml ppx_variants_conv-113.33.00+4.03/src/ppx_variants_conv.ml
--- ppx_variants_conv-113.33.00/src/ppx_variants_conv.ml	2016-03-09 16:44:55.000000000 +0100
+++ ppx_variants_conv-113.33.00+4.03/src/ppx_variants_conv.ml	2016-03-22 15:13:51.000000000 +0100
@@ -34,7 +34,7 @@
 
   let lambda_sig loc arg_tys body_ty =
     List.fold_right arg_tys ~init:body_ty ~f:(fun arg_ty acc ->
-      ptyp_arrow ~loc "" arg_ty acc)
+      ptyp_arrow ~loc Nolabel arg_ty acc)
   ;;
 
   let lambda_sig' loc arg_tys body_ty =
@@ -94,9 +94,14 @@
   let constructor body_ty cd : Variant_definition.t =
     if cd.pcd_res <> None then
       Location.raise_errorf ~loc:cd.pcd_loc "GADTs are not supported by variantslib";
+    let pcd_args =
+      match cd.pcd_args with
+      | Pcstr_tuple pcd_args -> pcd_args
+      | Pcstr_record _ -> failwith "Pcstr_record not supported"
+    in
     { name = cd.pcd_name.txt
     ; body_ty
-    ; arg_tys = cd.pcd_args
+    ; arg_tys = pcd_args
     ; kind = `Normal
     }
 
@@ -120,7 +125,7 @@
     ptyp_constr ~loc (Located.lident ~loc ty_name) tps
 
   let label_arg _loc name ty =
-    (String.lowercase name, ty)
+    (Asttypes.Labelled (String.lowercase name), ty)
   ;;
 
   let variant_arg loc f v =
@@ -186,7 +191,7 @@
     in
     let types = List.map variants ~f in
     let t = Create.lambda_sig' loc
-      (("", variant_type) :: types) result_type in
+      ((Nolabel, variant_type) :: types) result_type in
     psig_value ~loc (value_description ~loc ~name:(Located.mk ~loc "map") ~type_:t
                        ~prim:[])
   ;;
@@ -316,7 +321,7 @@
       | None    -> name
       | Some n  -> n
     in
-    (l, pvar ~loc name)
+    (Asttypes.Labelled l, pvar ~loc name)
   ;;
 
   let label_arg_fun loc name =
@@ -408,7 +413,7 @@
       List.map variants ~f:(fun variant ->
         label_arg_fun loc (variant_name_to_string variant.V.name))
     in
-    let lambda = Create.lambda loc (("", [%pat? t__]) :: patterns) body in
+    let lambda = Create.lambda loc ((Nolabel, [%pat? t__]) :: patterns) body in
     [%stri let map = [%e lambda] ]
   ;;