diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index c2d31220..1f6a7883 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -1109,6 +1109,7 @@ OCaml:
   - .mli
   - .mll
   - .mly
+  - .ml4
 
 ObjDump:
   type: data