diff --git a/sql/json/revision.metadata.schema.json b/sql/json/revision.metadata.schema.json
index cb37d7a0b..2dd797682 100644
--- a/sql/json/revision.metadata.schema.json
+++ b/sql/json/revision.metadata.schema.json
@@ -1,95 +1,101 @@
 {
     "$schema": "http://json-schema.org/schema#",
     "id": "http://softwareheritage.org/schemas/myschema.json",
 
     "definitions": {
         "person": {
             "type": "object",
             "properties": {
                 "name": {
                     "title": "full name",
                     "type": "string"
                 },
                 "email": {
                     "title": "email address",
                     "type": "string",
                     "format": "email"
                 }
             }
         },
         "pkgid": {
             "title": "debian source package identifier",
             "type": "array",
             "items": [
                 {
                     "title": "package name",
                     "type": "string"
                 },
                 {
                     "title": "package version",
                     "type": "string"
                 }
             ]
+        },
+        "archive_type": {
+            "title": "a file archive type (tar, zip, etc.)",
+            "description": "Most values are self-describing. Others are as follows:\n 'dsc' -> Debian source package",
+            "type": "string",
+            "enum": ["tar", "zip", "dsc"]
         }
     },
 
     "type": "object",
     "properties": {
 
         "original_artifact": {
             "type": "array",
             "items": {
                 "type": "object",
                 "properties": {
                     "name": { "type": "string" },
                     "length": { "type": "integer", "minimum": 0 },
                     "sha1": { "type": "string" },
                     "sha1_git": { "type": "string" },
                     "sha256": { "type": "string" },
-                    "archive_type": { "type": "string" }
+                    "archive_type": { "$ref": "#/definitions/archive_type" }
                 }
             }
         },
 
         "package_info": {
             "type": "object",
             "properties": {
                 "name": { "type": "string" },
                 "version": { "type": "string" },
                 "changelog": {
                     "type": "object",
                     "properties": {
                         "date": { "type": "string", "format": "date-time" },
                         "person": { "$ref": "#/definitions/person" },
                         "history": {
                             "type": "array",
                             "items": { "$ref": "#/definitions/pkgid" }
                         }
                     }
                 },
                 "maintainers": { 
                     "type": "object",
                     "properties": {
                     }
                 },
                 "pgp_signature": { 
                     "type": "object",
                     "properties": {
                         "date": { "type": "string", "format": "date-time" },
                         "keyid": { "type": "string" },
                         "person": { "$ref": "#/definitions/person" }
                     }
                 },
                 "lister_metadata": { 
                     "type": "object",
                     "properties": {
                         "id": { "type": "integer" },
                         "lister": { "type": "string" }
                     }
                 }
             }
         }
 
     }
         
 }