diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 4d36d8d0..7ce1d410 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -1005,6 +1005,7 @@ HTML:
   - .htm
   - .st
   - .xhtml
+  - .xht
 
 HTML+Django:
   type: markup