diff --git a/pyproject.toml b/pyproject.toml
index b5dfad8..c5ac2eb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,3 +36,9 @@ documentation = "https://wfdb.readthedocs.io/"
 [tool.black]
 line-length = 80
 target-version = ['py37']
+
+[tool.hatch.build.targets.sdist]
+exclude = [
+    "/tests",
+    "/sample-data",
+]