diff --git a/lib/linguist/vendor.yml b/lib/linguist/vendor.yml
index 0eab82c7..270ad593 100644
--- a/lib/linguist/vendor.yml
+++ b/lib/linguist/vendor.yml
@@ -56,7 +56,8 @@
 - animate.min.css
 
 # Vendored dependencies
-- thirdparty/
+- third[-_]?party/
+- 3rd[-_]?party/
 - vendors?/
 - extern(al)?/