diff --git a/cluster/gce/config-default.sh b/cluster/gce/config-default.sh
index df5c917178f..ee8ac8fe04c 100755
--- a/cluster/gce/config-default.sh
+++ b/cluster/gce/config-default.sh
@@ -63,7 +63,7 @@ function increment_ipv4 {
 }
 
 node_count="${NUM_MINIONS}"
-next_node="10.244.0.0"
+next_node="${KUBE_GCE_CLUSTER_CLASS_B:-10.244}.0.0"
 node_subnet_size=24
 node_subnet_count=$((2 ** (32-$node_subnet_size)))
 subnets=()
@@ -73,7 +73,7 @@ for ((node_num=0; node_num<node_count; node_num++)); do
   next_node=$(increment_ipv4 $next_node $node_subnet_count)
 done
 
-CLUSTER_IP_RANGE="10.244.0.0/16"
+CLUSTER_IP_RANGE="${KUBE_GCE_CLUSTER_CLASS_B:-10.244}.0.0/16"
 MINION_IP_RANGES=($(eval echo "${subnets[@]}"))
 
 MINION_SCOPES=("storage-ro" "compute-rw" "https://www.googleapis.com/auth/monitoring")
diff --git a/cluster/gce/config-test.sh b/cluster/gce/config-test.sh
index 11ed986eb8d..6d4e96b4d9d 100755
--- a/cluster/gce/config-test.sh
+++ b/cluster/gce/config-test.sh
@@ -33,10 +33,9 @@ INSTANCE_PREFIX="${KUBE_GCE_INSTANCE_PREFIX:-e2e-test-${USER}}"
 MASTER_NAME="${INSTANCE_PREFIX}-master"
 MASTER_TAG="${INSTANCE_PREFIX}-master"
 MINION_TAG="${INSTANCE_PREFIX}-minion"
-CLUSTER_IP_RANGE="10.245.0.0/16"
-MINION_IP_RANGES=($(eval echo "10.245.{1..${NUM_MINIONS}}.0/24"))
+CLUSTER_IP_RANGE="${KUBE_GCE_CLUSTER_CLASS_B:-10.245}.0.0/16"
+MINION_IP_RANGES=($(eval echo "${KUBE_GCE_CLUSTER_CLASS_B:-10.245}.{1..${NUM_MINIONS}}.0/24"))
 MASTER_IP_RANGE="${MASTER_IP_RANGE:-10.246.0.0/24}"
-
 MINION_SCOPES=("storage-ro" "compute-rw")
 # Increase the sleep interval value if concerned about API rate limits. 3, in seconds, is the default.
 POLL_SLEEP_INTERVAL=3