diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 186670dd..cf5ce08f 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -999,6 +999,7 @@ TeX:
   - .cls
   - .dtx
   - .ins
+  - .ltx
   - .sty
   - .tex
   - .toc