diff --git a/MANIFEST.in b/MANIFEST.in
index aac0c2ccae..041bdffbdf 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -6,3 +6,4 @@ include README.md
 include LICENSE
 
 prune tests
+recursive-include monai/csrc *.cpp *.cu *.h *.cuh