diff --git a/pyproject.toml b/pyproject.toml
index bef7851..f660802 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,6 +23,9 @@ tinycss2 = "^1.3.0"
 
 [tool.poetry.dev-dependencies]
 
+[tool.poetry.packages]
+include = ["cpm", "cpm.*"]
+
 [tool.poetry.scripts]
 
 [build-system]