diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0d2cb8c3..d18998b1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -51,6 +51,7 @@ jobs:
         run: |
           if ! crystal tool format --check; then
             crystal tool format
+            git diff
             exit 1
           fi