diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b20b62d769ba88fd7d0199101e3e7630f41cf040..d0721e8586d903b4bfefbd6fd2ffaacafd431e59 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -41,7 +41,7 @@ variables:
 
 # general Ubuntu job template
 .ubuntu-template-job-base: &ubuntu-job-base
-  image: ubuntu:22.04
+  image: gitlab-registry.cern.ch/mbandier/geant4-ubuntu:latest
   rules:
     - when: always
 
@@ -53,14 +53,9 @@ variables:
 .ubuntu-template-job-default: &ubuntu-job
   <<: *ubuntu-job-base
   before_script:
-    - apt-get update -qq && apt-get install -y -qq apt-utils git wget unzip build-essential freeglut3-dev libboost-all-dev qtbase5-dev libqt5opengl5-dev mercurial libeigen3-dev libsqlite3-dev nlohmann-json3-dev libexpat1-dev libxerces-c-dev libhdf5-dev libhepmc3-dev cmake
-    - apt-get install distro-info-data lsb-release
-    - wget https://ecsft.cern.ch/dist/cvmfs/cvmfs-release/cvmfs-release-latest_all.deb
-    - dpkg -i cvmfs-release-latest_all.deb
-    - rm -f cvmfs-release-latest_all.deb
-    - apt-get update -qq
-    - apt-get install -y -qq cvmfs cvmfs-config-default
-    - cvmfs_config setup
+  - pwd; ls
+  - echo "Hello, working from the custom docker image!"
+
 
 
 # .ubuntu-template-job-registry: &ubuntu-job-registry