diff --git a/types/ds_types.anubis b/types/ds_types.anubis
index 257925e..6890c56 100644
--- a/types/ds_types.anubis
+++ b/types/ds_types.anubis
@@ -105,12 +105,27 @@ public define DS_Alternative
   alternative(alt_name, no_comment, components)
 .
 
+public type DS_Type_Generation:
+  no_message,
+  message.
+  
 public type DS_Type:
-  ds_type(
+  ds_type
+  (
     String                type_name,
+    DS_Type_Generation    type_generation,
     List(DS_Alternative)  ds_alts
   ).
 
+public define DS_Type
+  ds_type
+  (
+    String                type_name,
+    List(DS_Alternative)  ds_alts
+  )=
+  ds_type(type_name, message, ds_alts)
+.
+  
 public type Extern_type:
   extern(String type_name, String ext_read)
 .
@@ -161,7 +176,7 @@ public define List(Extern_type)
   (
     DS_Type ds_type
   )=
-  since ds_type is ds_type(_, ds_alternatives),
+  since ds_type is ds_type(_, _, ds_alternatives),
   extract_extern_type(ds_alternatives, [])
 .
 
@@ -364,7 +379,7 @@ public define String
   (
     DS_Type _ds_type
   )=
-  since _ds_type is ds_type(type_name, ds_alts),
+  since _ds_type is ds_type(type_name, _, ds_alts),
   with type_length     = alternative_type_max_length(ds_alts,0)+2,
        alt_name_length = alternative_name_max_length(ds_alts, 0),
       type_name_length = alternative_type_name_max_length(ds_alts,0),
--
libgit2 0.21.4