diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 36fd8c9720697d10b38f6ab9a9572e9c6bad43e0..6397297f9e72b0c3c254ed257621c8435d862fe4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -54,8 +54,10 @@ lint:
   stage: checks
   script:
 #    - poetry config virtualenvs.in-project true
-    - poetry install --no-dev
+    - poetry install
     - make pylint
+  variables:
+    PYTHON_VERSION: "3.9"
 
 .tests:
   extends: .changes