diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index be30de5c..2e14def8 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,6 +12,7 @@ image: fluiddyn/python3-stable:lastest
 #     - tox -e py39,py39-fft,codecov
 
 validate_code:
+  image: python:3.9
   script:
     - pip index versions flit-core
     - pip install requests