diff --git a/setup.py b/setup.py
index 9ad4178bd..7850e48a8 100644
--- a/setup.py
+++ b/setup.py
@@ -327,7 +327,7 @@ def _get_interop_filename():
                 sources.append(os.path.join(root, filename))
 
     for root, dirnames, filenames in os.walk("tools"):
-        for ext in (".exe", ".py"):
+        for ext in (".exe", ".py", ".c", ".h"):
             for filename in fnmatch.filter(filenames, "*" + ext):
                 sources.append(os.path.join(root, filename))