diff --git a/pre-upload.py b/pre-upload.py
index 77ea6fe..2548572 100644
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -228,7 +228,8 @@
       r"/src/third_party/u-boot/",
       r".*\.ebuild$",
       r".*\.eclass$",
-      r".*/[M|m]akefile$"
+      r".*/[M|m]akefile$",
+      r".*\.mk$"
   ]
 
   errors = []