diff --git a/.gitlab-ci.pre-commit-run.bash b/.gitlab-ci.pre-commit-run.bash
index 704e716956ec58c44775b2b11d696e71560a6650..54d829b4723eb33423117f421427bcd95aebbd54 100644
--- a/.gitlab-ci.pre-commit-run.bash
+++ b/.gitlab-ci.pre-commit-run.bash
@@ -44,7 +44,7 @@ pre_commit_run() (
 		fetch_ref $CI_COMMIT_BEFORE_SHA
 	elif [[ -v CI_MERGE_REQUEST_TARGET_BRANCH_NAME ]]; then
 		find_lca $CI_MERGE_REQUEST_SOURCE_BRANCH_NAME $CI_MERGE_REQUEST_TARGET_BRANCH_NAME
-	elif [[ $CI_COMMIT_BRANCH != $CI_DEFAULT_BRANCH ]]; then
+	elif [[ -v CI_COMMIT_BRANCH ]] && [[ $CI_COMMIT_BRANCH != $CI_DEFAULT_BRANCH ]]; then
 		find_lca $CI_COMMIT_BRANCH $CI_DEFAULT_BRANCH
 	fi