diff --git a/index.json b/index.json
index 5cce10b5..c542e9eb 100644
--- a/index.json
+++ b/index.json
@@ -6034,7 +6034,7 @@
       "filename": "index.html"
     },
     "title": "Manifest Incubations",
-    "source": "spec",
+    "source": "specref",
     "shortTitle": "Manifest Incubations",
     "categories": [
       "browser"