diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5d5c08ee55f6d48a1d2e1611d7ee19c089e96139..348e34eb6e8bf1c27b8173af92cdc7f154e67dce 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -5,7 +5,7 @@
 
 # Official language image. Look for the different tagged releases at:
 # https://hub.docker.com/r/library/python/tags/
-image: python:latest
+image: python:3.9
 
 # Change pip's cache directory to be inside the project directory since we can
 # only cache local items.