diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b742813fd89b8e8297d6f8667d9fe23a085c8d7a..f5d308f71614345ed3f475172e02af4732c91950 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -30,7 +30,7 @@ run_black:
   stage: lint
   script:
     - python -m black --version
-    - python -m black --check .
+    - python -m black --check --diff .
   allow_failure: true
 
 run_flake8: