diff --git a/cluster/gce/util.sh b/cluster/gce/util.sh
index 5a0c6ad5339..852ba0ee087 100755
--- a/cluster/gce/util.sh
+++ b/cluster/gce/util.sh
@@ -596,6 +596,7 @@ function kube-up() {
   set_num_migs
 
   if [[ ${KUBE_USE_EXISTING_MASTER:-} == "true" ]]; then
+    detect-master
     parse-master-env
     create-nodes
   elif [[ ${KUBE_REPLICATE_EXISTING_MASTER:-} == "true" ]]; then