diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c9224a09b520edab6ec40d15105b5ee5bb2d99ca..ea9866d2cba9b9c5980186efd5c3bde4eece68da 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