diff --git a/vendor/html-theme-ref b/vendor/html-theme-ref
index 1174f93..21e57f7 160000
--- a/vendor/html-theme-ref
+++ b/vendor/html-theme-ref
@@ -1 +1 @@
-Subproject commit 1174f93d66866d84709e922d704d8e795dac7f62
+Subproject commit 21e57f732a5d9fcd6b53f701a7b703979cd20251