diff --git a/test/cmd/apps.sh b/test/cmd/apps.sh
index 8b2a585af87..4c6c3c2d9c4 100755
--- a/test/cmd/apps.sh
+++ b/test/cmd/apps.sh
@@ -640,7 +640,7 @@ run_rs_tests() {
   # Post-condition: no replica set exists
   kube::test::get_object_assert rs "{{range.items}}{{${id_field:?}}}:{{end}}" ''
 
-  if kube::test::if_supports_resource "${horizontalpodautoscalers:?}" ; then
+  if kube::test::if_supports_resource "horizontalpodautoscalers" ; then
     ### Auto scale replica set
     # Pre-condition: no replica set exists
     kube::test::get_object_assert rs "{{range.items}}{{${id_field:?}}}:{{end}}" ''
diff --git a/test/cmd/legacy-script.sh b/test/cmd/legacy-script.sh
index 26cc9fd5889..d11e1aa1e03 100755
--- a/test/cmd/legacy-script.sh
+++ b/test/cmd/legacy-script.sh
@@ -83,8 +83,6 @@ clusterroles="clusterroles"
 configmaps="configmaps"
 csr="csr"
 deployments="deployments"
-export horizontalpodautoscalers="horizontalpodautoscalers"
-export metrics="metrics"
 namespaces="namespaces"
 nodes="nodes"
 persistentvolumeclaims="persistentvolumeclaims"
@@ -98,10 +96,8 @@ secrets="secrets"
 serviceaccounts="serviceaccounts"
 services="services"
 statefulsets="statefulsets"
-export static="static"
 storageclass="storageclass"
 subjectaccessreviews="subjectaccessreviews"
-export selfsubjectaccessreviews="selfsubjectaccessreviews"
 customresourcedefinitions="customresourcedefinitions"
 daemonsets="daemonsets"
 controllerrevisions="controllerrevisions"
@@ -335,7 +331,10 @@ runTests() {
     [ "$(kubectl get nodes -o go-template='{{ .apiVersion }}' "${kube_flags[@]}")" == "v1" ]
   fi
 
-  id_field=".metadata.name"
+  # Define helper variables for fields to prevent typos.
+  # They will be used in some other files under test/cmd,
+  # Let's export them as https://github.com/koalaman/shellcheck/wiki/SC2034 suggested.
+  export id_field=".metadata.name"
   export labels_field=".metadata.labels"
   export annotations_field=".metadata.annotations"
   export service_selector_field=".spec.selector"
diff --git a/test/cmd/proxy.sh b/test/cmd/proxy.sh
index 29eee0b1da1..98e30fbfcfa 100755
--- a/test/cmd/proxy.sh
+++ b/test/cmd/proxy.sh
@@ -27,10 +27,10 @@ run_kubectl_local_proxy_tests() {
   start-proxy
   check-curl-proxy-code /api/kubernetes 404
   check-curl-proxy-code /api/v1/namespaces 200
-  if kube::test::if_supports_resource "${metrics:?}" ; then
+  if kube::test::if_supports_resource "metrics" ; then
     check-curl-proxy-code /metrics 200
   fi
-  if kube::test::if_supports_resource "${static:?}" ; then
+  if kube::test::if_supports_resource "static" ; then
     check-curl-proxy-code /static/ 200
   fi
   stop-proxy
@@ -45,7 +45,7 @@ run_kubectl_local_proxy_tests() {
   start-proxy /custom
   check-curl-proxy-code /custom/api/kubernetes 404
   check-curl-proxy-code /custom/api/v1/namespaces 200
-  if kube::test::if_supports_resource "${metrics}" ; then
+  if kube::test::if_supports_resource "metrics" ; then
     check-curl-proxy-code /custom/metrics 200
   fi
   check-curl-proxy-code /custom/api/v1/namespaces 200