--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,7 +8,7 @@ version_scheme = "post-release"
 
 [tool.setuptools.packages.find]
-include = ["sitka_spruce"]
+include = ["sitka_spruce", "sitka_spruce.*"]
 
 [tool.coverage.run]
 omit = ["tests/*"]