diff --git a/csaf_2.1/json_schema/csaf_json_schema.json b/csaf_2.1/json_schema/csaf_json_schema.json
index 1c42ccb52..815323696 100644
--- a/csaf_2.1/json_schema/csaf_json_schema.json
+++ b/csaf_2.1/json_schema/csaf_json_schema.json
@@ -96,6 +96,7 @@
               "language",
               "legacy",
               "patch_level",
+              "platform",
               "product_family",
               "product_name",
               "product_version",