diff --git a/lib/modules/datasource/custom/readme.md b/lib/modules/datasource/custom/readme.md
index 7391076f901b65..b3915695c0262d 100644
--- a/lib/modules/datasource/custom/readme.md
+++ b/lib/modules/datasource/custom/readme.md
@@ -70,7 +70,8 @@ All available options:
       "changelogUrl": "https://github.com/demo-org/demo/blob/main/CHANGELOG.md#v0710",
       "sourceUrl": "https://github.com/demo-org/demo",
       "sourceDirectory": "monorepo/folder",
-      "digest": "c667f758f9e46e1d8111698e8d3a181c0b10f430"
+      "digest": "c667f758f9e46e1d8111698e8d3a181c0b10f430",
+      "isStable": true
     }
   ],
   "sourceUrl": "https://github.com/demo-org/demo",
diff --git a/lib/modules/datasource/custom/schema.ts b/lib/modules/datasource/custom/schema.ts
index 58a1df4f0ec30e..50c19b7ed948b1 100644
--- a/lib/modules/datasource/custom/schema.ts
+++ b/lib/modules/datasource/custom/schema.ts
@@ -11,6 +11,7 @@ export const ReleaseResultZodSchema = z.object({
         sourceDirectory: z.string().optional(),
         changelogUrl: z.string().optional(),
         digest: z.string().optional(),
+        isStable: z.boolean().optional(),
       })
       .transform((input) => {
         return {