diff --git a/src/generation/types.anubis b/src/generation/types.anubis
index 782904c..5c3ab39 100644
--- a/src/generation/types.anubis
+++ b/src/generation/types.anubis
@@ -123,7 +123,12 @@ public define Maybe(One)
   since _generate_extract_web_arg(columns, [], 0) is ((List(String))list_of_web_arg, (Int) nb_closure),
   //generate the type of the table that contain all components 
   if write_string(stream, 
-     "\n\ndefine Maybe("+type_name+")\n  extract_from_web_arg\n  (\n    List(Web_arg) lwa\n  )=\n"+   //head of the definition
+     "\n\ndefine Maybe("+type_name+")\n"+
+     "  extract_from_web_arg\n"+
+     "  (\n"+
+     "    List(Web_arg) lwa,\n"+
+     "    String prefix\n"+
+     "  )=\n"+   //head of the definition
      to_String(list_of_web_arg)+                       //all editable components of the type
      "    success(\n"+generate_constructor(name, columns, "      ")+")\n"+         //generate type construction with values got from web arg
      "  "+fill(nb_closure, '}')+          //add close } according to number of web arg 
@@ -291,7 +296,7 @@ public define Maybe(One)
      "    SQLite3DataBase db,\n"+
      "    List(Web_arg)   lwa\n"+
      "  )=\n"+
-     "  if extract_from_web_arg(lwa) is\n"+
+     "  if extract_from_web_arg(lwa, \"\") is\n"+
      "  {\n"+
      "    failure         then failure,\n"+
      "    success("+name+")  then success(update_"+name+"(db, "+name+"))\n"+
--
libgit2 0.21.4