diff --git a/cluster/gce/config-default.sh b/cluster/gce/config-default.sh
index 659af93d788..476c505bbb0 100755
--- a/cluster/gce/config-default.sh
+++ b/cluster/gce/config-default.sh
@@ -42,7 +42,7 @@ KUBE_DELETE_NODES=${KUBE_DELETE_NODES:-true}
 KUBE_DELETE_NETWORK=${KUBE_DELETE_NETWORK:-false}
 
 MASTER_OS_DISTRIBUTION=${KUBE_MASTER_OS_DISTRIBUTION:-${KUBE_OS_DISTRIBUTION:-gci}}
-NODE_OS_DISTRIBUTION=${KUBE_NODE_OS_DISTRIBUTION:-${KUBE_OS_DISTRIBUTION:-debian}}
+NODE_OS_DISTRIBUTION=${KUBE_NODE_OS_DISTRIBUTION:-${KUBE_OS_DISTRIBUTION:-gci}}
 if [[ "${MASTER_OS_DISTRIBUTION}" == "coreos" ]]; then
     MASTER_OS_DISTRIBUTION="container-linux"
 fi
@@ -63,15 +63,16 @@ if [[ "${NODE_OS_DISTRIBUTION}" == "debian" ]]; then
     NODE_ACCELERATORS=""
 fi
 
-# By default a cluster will be started with the master on GCI and nodes on
-# containervm. If you are updating the containervm version, update this
-# variable. Also please update corresponding image for node e2e at:
+# By default a cluster will be started with the master and nodes
+# on Container-optimized OS (cos, previously known as gci). If
+# you are updating the os image versions, update this variable.
+# Also please update corresponding image for node e2e at:
 # https://github.com/kubernetes/kubernetes/blob/master/test/e2e_node/jenkins/image-config.yaml
 CVM_VERSION=${CVM_VERSION:-container-vm-v20170627}
 GCI_VERSION=${KUBE_GCI_VERSION:-cos-stable-59-9460-64-0}
 MASTER_IMAGE=${KUBE_GCE_MASTER_IMAGE:-}
 MASTER_IMAGE_PROJECT=${KUBE_GCE_MASTER_PROJECT:-cos-cloud}
-NODE_IMAGE=${KUBE_GCE_NODE_IMAGE:-${CVM_VERSION}}
+NODE_IMAGE=${KUBE_GCE_NODE_IMAGE:-${GCI_VERSION}}
 GCE_API_ENDPOINT=${KUBE_GCE_API_ENDPOINT:-}
 NODE_IMAGE_PROJECT=${KUBE_GCE_NODE_PROJECT:-cos-cloud}
 CONTAINER_RUNTIME=${KUBE_CONTAINER_RUNTIME:-docker}
diff --git a/cluster/gce/config-test.sh b/cluster/gce/config-test.sh
index 76374026179..28ed5bcca96 100755
--- a/cluster/gce/config-test.sh
+++ b/cluster/gce/config-test.sh
@@ -62,9 +62,11 @@ if [[ "${NODE_OS_DISTRIBUTION}" == "debian" ]]; then
     NODE_ACCELERATORS=""
 fi
 
-# By default a cluster will be started with the master on GCI and nodes on
-# containervm. If you are updating the containervm version, update this
-# variable. Also please update corresponding image for node e2e at:
+# By default a cluster will be started with the master and nodes
+# on Container-VM, the deprecated OS. Some tests assume container-VM,
+# and only when that is fixed can we use Container-Optimized OS
+# (cos, gci) as we do in config-default.sh.
+# Also please update corresponding image for node e2e at:
 # https://github.com/kubernetes/kubernetes/blob/master/test/e2e_node/jenkins/image-config.yaml
 CVM_VERSION=${CVM_VERSION:-container-vm-v20170627}
 GCI_VERSION=${KUBE_GCI_VERSION:-cos-stable-59-9460-64-0}
diff --git a/cluster/kubemark/gce/config-default.sh b/cluster/kubemark/gce/config-default.sh
index dd9df48f807..616f8ad4775 100644
--- a/cluster/kubemark/gce/config-default.sh
+++ b/cluster/kubemark/gce/config-default.sh
@@ -35,7 +35,7 @@ REGISTER_MASTER_KUBELET=${REGISTER_MASTER:-false}
 PREEMPTIBLE_NODE=${PREEMPTIBLE_NODE:-false}
 
 MASTER_OS_DISTRIBUTION=${KUBE_MASTER_OS_DISTRIBUTION:-gci}
-NODE_OS_DISTRIBUTION=${KUBE_NODE_OS_DISTRIBUTION:-debian}
+NODE_OS_DISTRIBUTION=${KUBE_NODE_OS_DISTRIBUTION:-gci}
 MASTER_IMAGE=${KUBE_GCE_MASTER_IMAGE:-cos-stable-59-9460-64-0}
 MASTER_IMAGE_PROJECT=${KUBE_GCE_MASTER_PROJECT:-cos-cloud}