diff --git a/cluster/saltbase/salt/generate-cert/make-ca-cert.sh b/cluster/saltbase/salt/generate-cert/make-ca-cert.sh
index 2e8eb8c2221..c77ca621736 100755
--- a/cluster/saltbase/salt/generate-cert/make-ca-cert.sh
+++ b/cluster/saltbase/salt/generate-cert/make-ca-cert.sh
@@ -46,7 +46,7 @@ if [[ -n "${extra_sans}" ]]; then
   sans="${sans},${extra_sans}"
 fi
 
-tmpdir=$(mktemp -d --tmpdir kubernetes_cacert.XXXXXX)
+tmpdir=$(mktemp -d -t kubernetes_cacert.XXXXXX)
 trap 'rm -rf "${tmpdir}"' EXIT
 cd "${tmpdir}"