diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 5f492c54..4acff585 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -1267,6 +1267,7 @@ TeX:
   - .ltx
   - .mkii
   - .mkiv
+  = .mkvi
   - .sty
   - .toc