diff --git a/MANIFEST.in b/MANIFEST.in
index 9ec4e0b6c9ba6323d76b145c7d5400ebc1f7936d..fdbf85c0dc1a99f5e0f094203094bd875059e377 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,5 +1,6 @@
 include README.md
 include COPYING.txt
 include RELEASE-VERSION
+global-include *.pyx
 include versioneer.py
 include lbmpy/_version.py