diff --git a/MANIFEST.in b/MANIFEST.in
index de340d48ded7..85caada2a1bd 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -19,3 +19,4 @@ recursive-include lib *
 recursive-include extern *
 include versioneer.py
 include lib/matplotlib/_version.py
+include tests.py