diff --git a/compiler/global/modules.ml b/compiler/global/modules.ml
index 7a72408..c9b1c4a 100644
--- a/compiler/global/modules.ml
+++ b/compiler/global/modules.ml
@@ -164,6 +164,8 @@ let add_const f v =
 (** Same as add_value but without checking for redefinition *)
 let replace_value f v =
   g_env.values <- QualEnv.add f v g_env.values
+let replace_type f v =
+  g_env.types <- QualEnv.add f v g_env.types
 
 (** { 3 Find functions look in the global environement, nothing more } *)
 
diff --git a/compiler/heptagon/analysis/typing.ml b/compiler/heptagon/analysis/typing.ml
index fbd3854..a24d88a 100644
--- a/compiler/heptagon/analysis/typing.ml
+++ b/compiler/heptagon/analysis/typing.ml
@@ -1096,10 +1096,28 @@ let typing_const_dec cd =
   let se = expect_static_exp QualEnv.empty ty cd.c_value in
     { cd with c_value = se; c_type = ty }
 
+let typing_typedec td =
+  let tydesc = match td.t_desc with
+    | Type_abs -> Type_abs
+    | Type_enum(tag_list) -> Type_enum tag_list
+    | Type_alias t ->
+        let t = check_type QualEnv.empty t in
+          replace_type td.t_name (Talias t);
+          Type_alias t
+    | Type_struct(field_ty_list) ->
+        let typing_field { f_name = f; f_type = ty } =
+          { f_name = f; f_type = check_type QualEnv.empty ty }
+        in
+        let field_ty_list = List.map typing_field field_ty_list in
+          replace_type td.t_name (Tstruct field_ty_list);
+          Type_struct field_ty_list
+  in
+    { td with t_desc = tydesc }
+
 let program p =
   let program_desc pd = match pd with
     | Pnode n -> Pnode (node n)
     | Pconst c -> Pconst (typing_const_dec c)
-    | _ -> pd
+    | Ptype t -> Ptype (typing_typedec t)
   in
   { p with p_desc = List.map program_desc p.p_desc }