diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 24276f7..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=master to=CI_BUILD_REF_NAME
+        - npx commitlint --from=$CI_BUILD_BEFORE_SHA
 
         # We need the covers and the previous version so we can generate the
         # "previously" chapter.