diff --git a/MANIFEST.in b/MANIFEST.in
index 5a1cc9d1b..99228ca91 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -10,3 +10,4 @@ include CHANGES.txt
 include LICENSE.txt
 include image_LICENSE.txt
 include image_LICENSE_PngSuite.txt
+include pyproject.toml