diff --git a/cluster/validate-cluster.sh b/cluster/validate-cluster.sh
index 3d10edd3892..da3cbcdc14e 100755
--- a/cluster/validate-cluster.sh
+++ b/cluster/validate-cluster.sh
@@ -57,7 +57,7 @@ if [[ "${KUBERNETES_PROVIDER:-}" == "gce" ]]; then
   # In multizone mode we need to add instances for all nodes in the region.
   if [[ "${MULTIZONE:-}" == "true" ]]; then
     EXPECTED_NUM_NODES=$(gcloud -q compute instances list --project="${PROJECT}" --format=[no-heading] --regexp="${NODE_INSTANCE_PREFIX}.*" \
-      --zones=$(gcloud -q compute zones list --project="${PROJECT}" --filter=region=${REGION} --format=[no-heading]\(name\) | tr "\n" "," | sed  "s/,$//") | wc -l)
+      --zones=$(gcloud -q compute zones list --project="${PROJECT}" --filter=region=${REGION} --format=csv[no-heading]\(name\) | tr "\n" "," | sed  "s/,$//") | wc -l)
     echo "Computing number of nodes, NODE_INSTANCE_PREFIX=${NODE_INSTANCE_PREFIX}, REGION=${REGION}, EXPECTED_NUM_NODES=${EXPECTED_NUM_NODES}"
   fi
 fi