diff --git a/MANIFEST.in b/MANIFEST.in
index 04b3e1fb9..94de4f3bf 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -12,3 +12,4 @@ prune docs/build
 recursive-include extras *
 recursive-include bin *
 recursive-include tests *
+global-exclude __pycache__ *.py[cod]