diff --git a/pyproject.toml b/pyproject.toml
index 3f6b845..a2b7230 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,6 +39,9 @@ python_version = "3.8"
 show_error_codes = true
 strict = true
 
+[tool.pdm.build]
+source-includes = ["CHANGES.rst", "tests"]
+
 [tool.pdm.version]
 source = "scm"