diff --git a/plugins/fabrique/charts/pg/kontinuous.values.schema.json b/plugins/fabrique/charts/pg/kontinuous.values.schema.json
index b665e1ab60..13483c4bdf 100644
--- a/plugins/fabrique/charts/pg/kontinuous.values.schema.json
+++ b/plugins/fabrique/charts/pg/kontinuous.values.schema.json
@@ -2,10 +2,14 @@
   "type": "object",
   "$schema": "http://json-schema.org/draft-07/schema#",
   "$id": "https://raw.githubusercontent.com/socialgouv/kontinuous/v1/plugins/fabrique/charts/pg/kontinuous.values.schema.json",
-  "title": "Kontinuous pg helm chart",
+  "title": "Kontinuous pg helm chart, see https://github.com/SocialGouv/kontinuous/blob/master/plugins/fabrique/charts/pg",
   "markdownDescription": "The [pg chart](https://github.com/SocialGouv/kontinuous/blob/master/plugins/fabrique/charts/pg) is a wrapper around [cnpg-cluster helm chart](https://github.com/SocialGouv/kontinuous/blob/master/plugins/fabrique/charts/pg)",
   "required": [],
   "properties": {
+    "~chart": {
+      "type": "string",
+      "const": "pg"
+    },
     "cnpg-cluster": {
       "title": "Kontinuous cnpg-cluster helm-chart",
       "markdownDescription": "The [cnpg-cluster helm chart](https://github.com/SocialGouv/helm-charts/tree/main/charts/cnpg-cluster) based on [https://cloudnative-pg.io](https://https://cloudnative-pg.io)\n\n💡 You can use the [meta `~tpl~` prefix](https://socialgouv.github.io/kontinuous/#/./advanced/build?id=meta-values-plugin-tpl) to make it a template",