diff --git a/docs/_data/develop_sidebar.json b/docs/_data/develop_sidebar.json
index c46b96fc24f..a28cfc333ae 100644
--- a/docs/_data/develop_sidebar.json
+++ b/docs/_data/develop_sidebar.json
@@ -8,11 +8,11 @@
       },
       {
          "title": "Performance Tips",
-         "url": "/custom-rules/performance-tips"
+         "url": "/custom-rules/performance-tips.html"
       },
       {
          "title": "Walker Design",
-         "url": "/custom-rules/walker-design"
+         "url": "/custom-rules/walker-design.html"
       },
       {
          "title": "Custom Formatters",