diff --git a/ci/lib.sh b/ci/lib.sh
index f7f1eeeb751..3cb2c158f64 100644
--- a/ci/lib.sh
+++ b/ci/lib.sh
@@ -18,6 +18,13 @@ clone_tests_repo()
 {
 	if [ -d "$tests_repo_dir" ]; then
 		[ -n "${CI:-}" ] && return
+		# git config --global --add safe.directory will always append
+		# the target to .gitconfig without checking the existence of
+		# the target, so it's better to check it before adding the target repo.
+		local sd="$(git config --global --get safe.directory ${tests_repo_dir} || true)"
+		if [ -z "${sd}" ]; then
+			git config --global --add safe.directory ${tests_repo_dir}
+		fi
 		pushd "${tests_repo_dir}"
 		git checkout "${branch}"
 		git pull