diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 00e0d8ee972e70ed094cc606018e116e8544098d..199796f4247d10dbe074a099acccc181d1c532a1 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -10,6 +10,13 @@ black:
   <<: *test_job
   script:
     - black $(git ls-files '*.py')
+    - git diff > black.patch
+    - if test "$(git status --porcelain | grep -Ev '\?\?' | wc -l)" -gt "0"; then git status --short; exit 1; fi
+  artifacts:
+    paths:
+      - black.patch
+    expire_in: "1 week"
+    when: on_failure
 
 pylint:
   <<: *test_job