diff --git a/pyproject.toml b/pyproject.toml
index 5dc054a..938ae8e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -67,6 +67,7 @@ include = [
     "GOALS",
     "Makefile",
     "NEWS",
+    "tests*",
     "TODO",
     "tox.ini",
 ]