diff --git a/setup.py b/setup.py
index 7dd6565..36e9ddf 100644
--- a/setup.py
+++ b/setup.py
@@ -30,5 +30,5 @@ def read(fname):
     url = 'http://github.com/btimby/haystack-sphinx/',
     download_url = download_url,
     license = 'GPLv3',
-    py_modules = ['sphinx_haystack'],
+    packages = ['sphinx_haystack', ],
 )