diff --git a/src/aeso_ast_infer_types.erl b/src/aeso_ast_infer_types.erl
index 1db77eb..6c02c2b 100644
--- a/src/aeso_ast_infer_types.erl
+++ b/src/aeso_ast_infer_types.erl
@@ -19,32 +19,15 @@
 %% Newly exported
 -export([ infer_const/2
         ]).
--export_type([ utype/0
-             , typesig/0
+-export_type([ typesig/0
              ]).
 
 -include("aeso_utils.hrl").
 
 -type env() :: aeso_tc_env:env().
 
--type utype() :: {fun_t, aeso_syntax:ann(), named_args_t(), [utype()] | var_args, utype()}
-               | {app_t, aeso_syntax:ann(), utype(), [utype()]}
-               | {tuple_t, aeso_syntax:ann(), [utype()]}
-               | aeso_syntax:id()  | aeso_syntax:qid()
-               | aeso_syntax:con() | aeso_syntax:qcon()  %% contracts
-               | aeso_syntax:tvar()
-               | {if_t, aeso_syntax:ann(), aeso_syntax:id(), utype(), utype()}  %% Can branch on named argument (protected)
-               | uvar().
-
--type uvar() :: {uvar, aeso_syntax:ann(), reference()}.
-
--type named_args_t() :: uvar() | [{named_arg_t, aeso_syntax:ann(), aeso_syntax:id(), utype(), aeso_syntax:expr()}].
-
 -type type() :: aeso_syntax:type().
 -type name() :: string().
--type typesig() :: {type_sig, aeso_syntax:ann(), type_constraints(), [aeso_syntax:named_arg_t()], [type()], type()}.
-
--type type_constraints() :: none | bytes_concat | bytes_split | address_to_contract | bytecode_hash.
 
 -type variance() :: invariant | covariant | contravariant | bivariant.
 
@@ -52,6 +35,12 @@
         when_option(pp_types, fun () -> io:format(Fmt, Args) end)).
 -define(CONSTRUCTOR_MOCK_NAME, "#__constructor__#").
 
+%% -- Duplicated types -------------------------------------------------------
+
+-type utype() :: aeso_tc_typedefs:utype().
+-type named_args_t() :: aeso_tc_typedefs:named_args_t().
+-type typesig() :: aeso_tc_typedefs:typesig().
+
 %% -- Moved functions --------------------------------------------------------
 
 name(A) -> aeso_tc_name_manip:name(A).
diff --git a/src/aeso_tc_constraints.erl b/src/aeso_tc_constraints.erl
index b1b0c62..01631d7 100644
--- a/src/aeso_tc_constraints.erl
+++ b/src/aeso_tc_constraints.erl
@@ -19,7 +19,7 @@
 
 -type uvar() :: {uvar, aeso_syntax:ann(), reference()}.
 -type named_args_t() :: uvar() | [{named_arg_t, aeso_syntax:ann(), aeso_syntax:id(), utype(), aeso_syntax:expr()}].
--type utype() :: aeso_ast_infer_types:utype().
+-type utype() :: aeso_tc_typedefs:utype().
 
 %% -- Duplicated macros ------------------------------------------------------
 
diff --git a/src/aeso_tc_env.erl b/src/aeso_tc_env.erl
index d8b27b4..03174a2 100644
--- a/src/aeso_tc_env.erl
+++ b/src/aeso_tc_env.erl
@@ -135,8 +135,8 @@ infer_const(A, B) -> aeso_ast_infer_types:infer_const(A, B).
 -type name() :: string().
 -type qname() :: [string()].
 -type type() :: aeso_syntax:type().
--type utype() :: aeso_ast_infer_types:utype().
--type typesig() :: aeso_ast_infer_types:typesig().
+-type utype() :: aeso_tc_typedefs:utype().
+-type typesig() :: aeso_tc_typedefs:typesig().
 
 %% -- Duplicated macros ------------------------------------------------------
 
diff --git a/src/aeso_tc_typedefs.erl b/src/aeso_tc_typedefs.erl
new file mode 100644
index 0000000..a16bc30
--- /dev/null
+++ b/src/aeso_tc_typedefs.erl
@@ -0,0 +1,20 @@
+-module(aeso_tc_typedefs).
+
+-export_type([utype/0, named_args_t/0, typesig/0]).
+
+-type uvar() :: {uvar, aeso_syntax:ann(), reference()}.
+
+-type named_args_t() :: uvar() | [{named_arg_t, aeso_syntax:ann(), aeso_syntax:id(), utype(), aeso_syntax:expr()}].
+
+-type utype() :: {fun_t, aeso_syntax:ann(), named_args_t(), [utype()] | var_args, utype()}
+               | {app_t, aeso_syntax:ann(), utype(), [utype()]}
+               | {tuple_t, aeso_syntax:ann(), [utype()]}
+               | aeso_syntax:id()  | aeso_syntax:qid()
+               | aeso_syntax:con() | aeso_syntax:qcon()  %% contracts
+               | aeso_syntax:tvar()
+               | {if_t, aeso_syntax:ann(), aeso_syntax:id(), utype(), utype()}  %% Can branch on named argument (protected)
+               | uvar().
+
+-type type_constraints() :: none | bytes_concat | bytes_split | address_to_contract | bytecode_hash.
+
+-type typesig() :: {type_sig, aeso_syntax:ann(), type_constraints(), [aeso_syntax:named_arg_t()], [aeso_syntax:type()], aeso_syntax:type()}.