diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c36356056..7c7b9554c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -20,15 +20,17 @@ pypi:
         - cp /keys/.pypirc ~/.pypirc
         - virtualenv env
         - source env/bin/activate
-        - pip install -U pip wheel setuptools
+        - pip install -U pip wheel setuptools check-manifest twine
         - XDG_CACHE_HOME=/cache pip3 install -Ur src/requirements.txt -r src/requirements/dev.txt
         - cd src
         - python setup.py sdist
         - pip install dist/pretix-*.tar.gz
         - python -m pretix migrate
         - python -m pretix check
-        - python setup.py sdist upload
-        - python setup.py bdist_wheel upload
+        - check-manifest
+        - python setup.py sdist bdist_wheel
+        - twine check dist/*
+        - twine upload dist/*
     tags:
         - python3
     only: