diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 5b366438..5526dd85 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -1381,6 +1381,7 @@ XML:
   - .tmLanguage
   - .tmPreferences
   - .tmSnippet
+  - .tmTheme
   - .tml
   - .ui
   - .vxml