diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5fcc4f0..b9a0a11 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,7 +12,7 @@ publish:
         - npm ci
 
         # Verify that the commits are good.
-        - npx commitlint --from=HEAD~1
+        - npx commitlint --from=$CI_BUILD_BEFORE_SHA
 
         # We need the covers and the previous version so we can generate the
         # "previously" chapter.