diff --git a/tools/apidoc/gen_toc.py b/tools/apidoc/gen_toc.py
index 7739aea633f..b6bc8f24d95 100644
--- a/tools/apidoc/gen_toc.py
+++ b/tools/apidoc/gen_toc.py
@@ -130,6 +130,7 @@ known_categories = {
     'Counter': 'AutoScale',
     'Condition': 'AutoScale',
     'Api': 'API Discovery',
+    'Region': 'Region',
     }