diff --git a/cluster/vagrant/util.sh b/cluster/vagrant/util.sh
index 10cae2dd2f8..4eedd82c96b 100644
--- a/cluster/vagrant/util.sh
+++ b/cluster/vagrant/util.sh
@@ -148,7 +148,7 @@ function create-provision-scripts {
     echo "DNS_REPLICAS='${DNS_REPLICAS:-}'"
     echo "RUNTIME_CONFIG='${RUNTIME_CONFIG:-}'"
     echo "ADMISSION_CONTROL='${ADMISSION_CONTROL:-}'"
-    echo "DOCKER_OPTS='${EXTRA_DOCKER_OPTS-}'"
+    echo "DOCKER_OPTS='${EXTRA_DOCKER_OPTS:-}'"
     echo "VAGRANT_DEFAULT_PROVIDER='${VAGRANT_DEFAULT_PROVIDER:-}'"
     echo "KUBELET_TOKEN='${KUBELET_TOKEN:-}'"
     echo "KUBE_PROXY_TOKEN='${KUBE_PROXY_TOKEN:-}'"
@@ -174,7 +174,7 @@ function create-provision-scripts {
       echo "CONTAINER_NETMASK='${MINION_CONTAINER_NETMASKS[$i]}'"
       echo "MINION_CONTAINER_SUBNETS=(${MINION_CONTAINER_SUBNETS[@]})"
       echo "CONTAINER_SUBNET='${CONTAINER_SUBNET}'"
-      echo "DOCKER_OPTS='${EXTRA_DOCKER_OPTS-}'"
+      echo "DOCKER_OPTS='${EXTRA_DOCKER_OPTS:-}'"
       echo "VAGRANT_DEFAULT_PROVIDER='${VAGRANT_DEFAULT_PROVIDER:-}'"
       echo "KUBELET_TOKEN='${KUBELET_TOKEN:-}'"
       echo "KUBE_PROXY_TOKEN='${KUBE_PROXY_TOKEN:-}'"