diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c57f10f..1e2e71d 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,7 +12,7 @@ black:
         - python3 -m pip install --upgrade pip
         - curl -sSL https://install.python-poetry.org | python3 -
         - export PATH="/root/.local/bin:$PATH"
-        - poetry install --with dev
+        - poetry install --with dev --no-root
     script:
         - poetry run black --quiet --check marietje
 
diff --git a/pyproject.toml b/pyproject.toml
index 5cdc0b1..1cc6570 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,7 +11,7 @@ authors = [
 	"Lars van Rhijn <l.vanrhijn@student.science.ru.nl>",
 ]
 maintainers = [
-	"Kees van Kempen <ru@keesvankempen.nl",
+	"Kees van Kempen <ru@keesvankempen.nl>",
 	"Lars van Rhijn <l.vanrhijn@student.science.ru.nl>",
 ]
 readme = "README.md"