diff --git a/core/MANIFEST.in b/core/MANIFEST.in
index ae20b86a84fd1..cb3a2b9ef4fa6 100644
--- a/core/MANIFEST.in
+++ b/core/MANIFEST.in
@@ -1,3 +1,4 @@
 include README.rst
 graft google
+graft unit_tests
 global-exclude *.pyc