diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d5db7940a..d07ba1f88 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -43,7 +43,7 @@ jobs:
     - name: Lint with Black
       run: |
         cd ..
-        python -m black qlib -l 120 --check
+        python -m black qlib -l 120 --check --diff
 
     - name: Unit tests with Pytest
       run: |