diff --git a/contents.json b/contents.json
index 90130386..f77cfd9a 100644
--- a/contents.json
+++ b/contents.json
@@ -29,10 +29,6 @@
       "title": "Conference",
       "id": "conference"
     },
-    {
-      "title": "Content Blocking",
-      "id": "content-blocking"
-    },
     {
       "title": "Developer",
       "id": "developer"
@@ -46,6 +42,11 @@
       "title": "Extension",
       "id": "extension"
     },
+    {
+      "title": "Content Blocking",
+      "id": "content-blocking",
+      "parent": "extension"
+    },
     {
       "title": "Finance",
       "id": "finance"