diff --git a/pyproject.toml b/pyproject.toml
index b5c5745..a6681dd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,6 +13,7 @@ license = "GPLv3"
 packages = [
   { include = "src" },
 ]
+virtualenvs.in-project = true
 
 [tool.mypy]
 exclude = [