diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c6f74696afd9a90b33463423a443f1ed72189972..0f2358a334912e33e4e896f5f7ae52adb5dac036 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -32,7 +32,7 @@ dev images:
     - if: $CI_COMMIT_BRANCH == "main"
   script:
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
-    - black --check ogscm
+    - black --diff --check ogscm
     - poetry install
     - poetry run ogscm compiler.py ogs.py -B --ogs off --cpu-target $CPU_TARGET
     - poetry run ogscm compiler.py ogs.py ogs_jupyter.py -B -R --build_args ' --progress=plain' --cvode --ccache --cpmcache --mfront --cpu-target $CPU_TARGET --cmake_args ' -DOGS_CPU_ARCHITECTURE=OFF -DOGS_BUILD_TESTING=OFF -DOGS_BUILD_PROCESSES=SteadyStateDiffusion' --runtime_base_image 'registry.opengeosys.org/ogs/ogs/jupyter/base-notebook-ubuntu:22.04_3.10'