diff --git a/trex.org b/trex.org
index 829ade4..80d146f 100644
--- a/trex.org
+++ b/trex.org
@@ -33,27 +33,29 @@ arrays are 0-based. Hence, we introduce the ~index~ type which is an
   authors of the file, and a textual description.
 
   #+NAME: metadata
-  | Variable      | Type  | Dimensions (for arrays) | Description                              |
-  |---------------+-------+-------------------------+------------------------------------------|
-  | ~code_num~    | ~int~ |                         | Number of codes used to produce the file |
-  | ~code~        | ~str~ | ~(metadata.code_num)~   | Names of the codes used                  |
-  | ~author_num~  | ~int~ |                         | Number of authors of the file            |
-  | ~author~      | ~str~ | ~(metadata.author_num)~ | Names of the authors of the file         |
-  | ~description~ | ~str~ |                         | Text describing the content of file      |
+  | Variable          | Type  | Dimensions (for arrays) | Description                              |
+  |-------------------+-------+-------------------------+------------------------------------------|
+  | ~code_num~        | ~int~ |                         | Number of codes used to produce the file |
+  | ~code~            | ~str~ | ~(metadata.code_num)~   | Names of the codes used                  |
+  | ~author_num~      | ~int~ |                         | Number of authors of the file            |
+  | ~author~          | ~str~ | ~(metadata.author_num)~ | Names of the authors of the file         |
+  | ~package_version~ | ~str~ |                         | TREXIO version used to produce the file  |
+  | ~description~     | ~str~ |                         | Text describing the content of file      |
 
   #+CALL: json(data=metadata, title="metadata")
   #+RESULTS:
-  :results:
+  :RESULTS:
   #+begin_src python :tangle trex.json
       "metadata": {
-             "code_num" : [ "int", []                        ]
-        ,        "code" : [ "str", [ "metadata.code_num" ]   ]
-        ,  "author_num" : [ "int", []                        ]
-        ,      "author" : [ "str", [ "metadata.author_num" ] ]
-        , "description" : [ "str", []                        ]
+		 "code_num" : [ "int", []                        ]
+	,            "code" : [ "str", [ "metadata.code_num" ]   ]
+	,      "author_num" : [ "int", []                        ]
+	,          "author" : [ "str", [ "metadata.author_num" ] ]
+	, "package_version" : [ "str", []                        ]
+	,     "description" : [ "str", []                        ]
       } ,
   #+end_src
-  :end:
+  :END:
 
 * Electron (electron group)