diff --git a/MANIFEST.in b/MANIFEST.in
index 70aa444..909afe4 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -3,5 +3,7 @@ graft src
 include CHANGELOG.rst
 include README.rst
 include publicsuffix2.LICENSE
+include tests.py
+include tests_mozilla.py
 
 global-exclude *.py[co] __pycache__ *.so *.pyd