diff --git a/cluster/common.sh b/cluster/common.sh
index 6d8770fcf41..08a69f3286e 100755
--- a/cluster/common.sh
+++ b/cluster/common.sh
@@ -750,6 +750,16 @@ EOF
   if [ -n "${ENABLE_CUSTOM_METRICS:-}" ]; then
     cat >>$file <<EOF
 ENABLE_CUSTOM_METRICS: $(yaml-quote ${ENABLE_CUSTOM_METRICS})
+EOF
+  fi
+  if [ -n "${ENABLE_METADATA_PROXY:-}" ]; then
+    cat >>$file <<EOF
+ENABLE_METADATA_PROXY: $(yaml-quote ${ENABLE_METADATA_PROXY})
+EOF
+  fi
+  if [ -n "${KUBE_FIREWALL_METADATA_SERVER:-}" ]; then
+    cat >>$file <<EOF
+KUBE_FIREWALL_METADATA_SERVER: $(yaml-quote ${KUBE_FIREWALL_METADATA_SERVER})
 EOF
   fi
   if [ -n "${FEATURE_GATES:-}" ]; then
diff --git a/cluster/gce/config-default.sh b/cluster/gce/config-default.sh
index a10e6ae0e52..3530a3dffb8 100755
--- a/cluster/gce/config-default.sh
+++ b/cluster/gce/config-default.sh
@@ -146,9 +146,11 @@ if [[ ${NETWORK_POLICY_PROVIDER:-} == "calico" ]]; then
 	NODE_LABELS="${NODE_LABELS},projectcalico.org/ds-ready=true"
 fi
 
-# Turn the simple metadata proxy on by default.
-ENABLE_METADATA_PROXY="${ENABLE_METADATA_PROXY:-simple}"
-if [[ ${ENABLE_METADATA_PROXY} != "false" ]]; then
+# Currently, ENABLE_METADATA_PROXY supports only "simple".  In the future, we
+# may add other options.
+ENABLE_METADATA_PROXY="${ENABLE_METADATA_PROXY:-}"
+# Apply the right node label if metadata proxy is on.
+if [[ ${ENABLE_METADATA_PROXY:-} == "simple" ]]; then
         NODE_LABELS="${NODE_LABELS},beta.kubernetes.io/metadata-proxy-ready=true"
 fi
 
diff --git a/cluster/gce/config-test.sh b/cluster/gce/config-test.sh
index d8ce945b0eb..98109324824 100755
--- a/cluster/gce/config-test.sh
+++ b/cluster/gce/config-test.sh
@@ -199,9 +199,8 @@ if [[ ${NETWORK_POLICY_PROVIDER:-} == "calico" ]]; then
 	NODE_LABELS="$NODE_LABELS,projectcalico.org/ds-ready=true"
 fi
 
-# Turn the simple metadata proxy on by default.
-ENABLE_METADATA_PROXY="${ENABLE_METADATA_PROXY:-simple}"
-if [[ ${ENABLE_METADATA_PROXY} != "false" ]]; then
+# Apply the right node label if metadata proxy is on.
+if [[ ${ENABLE_METADATA_PROXY:-} == "simple" ]]; then
         NODE_LABELS="${NODE_LABELS},beta.kubernetes.io/metadata-proxy-ready=true"
 fi