diff --git a/cluster/gce/config-default.sh b/cluster/gce/config-default.sh
index 2478613e85c..39ac48f7924 100755
--- a/cluster/gce/config-default.sh
+++ b/cluster/gce/config-default.sh
@@ -18,8 +18,8 @@
 # gcloud multiplexing for shared GCE/GKE tests.
 GCLOUD=gcloud
 ZONE=${KUBE_GCE_ZONE:-us-central1-b}
-MASTER_SIZE=n1-standard-1
-MINION_SIZE=n1-standard-1
+MASTER_SIZE=${MASTER_SIZE:-n1-standard-1}
+MINION_SIZE=${MINION_SIZE:-n1-standard-1}
 NUM_MINIONS=${NUM_MINIONS:-4}
 MINION_DISK_TYPE=pd-standard
 MINION_DISK_SIZE=100GB
diff --git a/cluster/gce/config-test.sh b/cluster/gce/config-test.sh
index d0b2fa89785..44a51d845a7 100755
--- a/cluster/gce/config-test.sh
+++ b/cluster/gce/config-test.sh
@@ -18,8 +18,8 @@
 # gcloud multiplexing for shared GCE/GKE tests.
 GCLOUD=gcloud
 ZONE=${KUBE_GCE_ZONE:-us-central1-b}
-MASTER_SIZE=g1-small
-MINION_SIZE=g1-small
+MASTER_SIZE=${MASTER_SIZE:-g1-small}
+MINION_SIZE=${MINION_SIZE:-g1-small}
 NUM_MINIONS=${NUM_MINIONS:-2}
 MINION_DISK_TYPE=pd-standard
 MINION_DISK_SIZE=100GB