diff --git a/site/theme.js b/site/theme.js
index 82282ac345683cd9f8096dc616c7d6df2a2e99eb..1fa3c8f2e1448f616f0fed7f8d1b76a31d86e262 100644
--- a/site/theme.js
+++ b/site/theme.js
@@ -75,6 +75,7 @@ module.exports = function(nico) {
           }
           if (directories.indexOf(itemDirectory) >= 0 ||
               item.filename.indexOf('CHANGELOG') >= 0) {
+            item.filename = item.filename.toLowerCase();
             categories[cat] = categories[cat] || [];
             categories[cat].push(item);
           }