diff --git a/MANIFEST.in b/MANIFEST.in
new file mode 100644
index 0000000..4cf955a
--- /dev/null
+++ b/MANIFEST.in
@@ -0,0 +1 @@
+recursive-include tests *.py *.nc *.png
diff --git a/pyproject.toml b/pyproject.toml
index b465f4e..79bdecd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "radclss"
-version = "2026.5.11.1"
+version = "2026.5.20"
 description = "Extracted Radar Columns and In Situ Sensors"
 readme = "README.md"
 requires-python = ">=3.10"