diff --git a/hack/.shellcheck_failures b/hack/.shellcheck_failures
index 6ba671b985..cbb262a115 100644
--- a/hack/.shellcheck_failures
+++ b/hack/.shellcheck_failures
@@ -45,13 +45,6 @@
 ./hack/build-cross.sh
 ./hack/build-go.sh
 ./hack/cherry_pick_pull.sh
-./hack/e2e-internal/e2e-cluster-size.sh
-./hack/e2e-internal/e2e-down.sh
-./hack/e2e-internal/e2e-grow-cluster.sh
-./hack/e2e-internal/e2e-shrink-cluster.sh
-./hack/e2e-internal/e2e-status.sh
-./hack/e2e-internal/e2e-up.sh
-./hack/e2e-node-test.sh
 ./hack/generate-bindata.sh
 ./hack/generate-docs.sh
 ./hack/get-build.sh
diff --git a/hack/e2e-internal/e2e-cluster-size.sh b/hack/e2e-internal/e2e-cluster-size.sh
index 8e604b9e37..817bd76caa 100755
--- a/hack/e2e-internal/e2e-cluster-size.sh
+++ b/hack/e2e-internal/e2e-cluster-size.sh
@@ -18,10 +18,10 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
-KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/../..
 
-: ${KUBECTL:=${KUBE_ROOT}/cluster/kubectl.sh}
-: ${KUBE_CONFIG_FILE:="config-test.sh"}
+: "${KUBECTL:=${KUBE_ROOT}/cluster/kubectl.sh}"
+: "${KUBE_CONFIG_FILE:="config-test.sh"}"
 
 export KUBECTL KUBE_CONFIG_FILE
 
diff --git a/hack/e2e-internal/e2e-down.sh b/hack/e2e-internal/e2e-down.sh
index 87bcb9a41e..ed318b6551 100755
--- a/hack/e2e-internal/e2e-down.sh
+++ b/hack/e2e-internal/e2e-down.sh
@@ -18,10 +18,10 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
-KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/../..
 
-: ${KUBECTL:=${KUBE_ROOT}/cluster/kubectl.sh}
-: ${KUBE_CONFIG_FILE:="config-test.sh"}
+: "${KUBECTL:=${KUBE_ROOT}/cluster/kubectl.sh}"
+: "${KUBE_CONFIG_FILE:="config-test.sh"}"
 
 export KUBECTL KUBE_CONFIG_FILE
 
diff --git a/hack/e2e-internal/e2e-grow-cluster.sh b/hack/e2e-internal/e2e-grow-cluster.sh
index 67b8603d26..65c7926e7e 100755
--- a/hack/e2e-internal/e2e-grow-cluster.sh
+++ b/hack/e2e-internal/e2e-grow-cluster.sh
@@ -14,18 +14,18 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/../..
 
-if [[ ! -z "${1:-}" ]]; then
+if [[ -n "${1:-}" ]]; then
   export KUBE_GCE_ZONE="${1}"
 fi
-if [[ ! -z "${2:-}" ]]; then
+if [[ -n "${2:-}" ]]; then
   export MULTIZONE="${2}"
 fi
-if [[ ! -z "${3:-}" ]]; then
+if [[ -n "${3:-}" ]]; then
   export KUBE_REPLICATE_EXISTING_MASTER="${3}"
 fi
-if [[ ! -z "${4:-}" ]]; then
+if [[ -n "${4:-}" ]]; then
   export KUBE_USE_EXISTING_MASTER="${4}"
 fi
 if [[ -z "${NUM_NODES:-}" ]]; then
diff --git a/hack/e2e-internal/e2e-shrink-cluster.sh b/hack/e2e-internal/e2e-shrink-cluster.sh
index 4e67b9813c..f94d57cc28 100755
--- a/hack/e2e-internal/e2e-shrink-cluster.sh
+++ b/hack/e2e-internal/e2e-shrink-cluster.sh
@@ -14,18 +14,18 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/../..
 
-if [[ ! -z "${1:-}" ]]; then
+if [[ -n "${1:-}" ]]; then
   export KUBE_GCE_ZONE="${1}"
 fi
-if [[ ! -z "${2:-}" ]]; then
+if [[ -n "${2:-}" ]]; then
   export MULTIZONE="${2}"
 fi
-if [[ ! -z "${3:-}" ]]; then
+if [[ -n "${3:-}" ]]; then
   export KUBE_DELETE_NODES="${3}"
 fi
-if [[ ! -z "${4:-}" ]]; then
+if [[ -n "${4:-}" ]]; then
   export KUBE_USE_EXISTING_MASTER="${4}"
 fi
 
diff --git a/hack/e2e-internal/e2e-status.sh b/hack/e2e-internal/e2e-status.sh
index 59a4559e9e..5e70929d76 100755
--- a/hack/e2e-internal/e2e-status.sh
+++ b/hack/e2e-internal/e2e-status.sh
@@ -18,10 +18,10 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
-KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/../..
 
-: ${KUBECTL:=${KUBE_ROOT}/cluster/kubectl.sh}
-: ${KUBE_CONFIG_FILE:="config-test.sh"}
+: "${KUBECTL:=${KUBE_ROOT}/cluster/kubectl.sh}"
+: "${KUBE_CONFIG_FILE:="config-test.sh"}"
 
 export KUBECTL KUBE_CONFIG_FILE
 
diff --git a/hack/e2e-internal/e2e-up.sh b/hack/e2e-internal/e2e-up.sh
index 24f4f6a587..eea6b94f19 100755
--- a/hack/e2e-internal/e2e-up.sh
+++ b/hack/e2e-internal/e2e-up.sh
@@ -18,10 +18,10 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
-KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/../..
 
-: ${KUBECTL:=${KUBE_ROOT}/cluster/kubectl.sh}
-: ${KUBE_CONFIG_FILE:="config-test.sh"}
+: "${KUBECTL:=${KUBE_ROOT}/cluster/kubectl.sh}"
+: "${KUBE_CONFIG_FILE:="config-test.sh"}"
 
 export KUBECTL KUBE_CONFIG_FILE
 
diff --git a/hack/e2e-node-test.sh b/hack/e2e-node-test.sh
index 4d697602ff..4a8bf6d66d 100755
--- a/hack/e2e-node-test.sh
+++ b/hack/e2e-node-test.sh
@@ -20,7 +20,7 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
-KUBE_ROOT=$(dirname "${BASH_SOURCE}")/..
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
 
 # For help output
 ARGHELP=""
@@ -40,4 +40,4 @@ echo "The equivalent of this invocation is: "
 echo "    make test-e2e-node ${ARGHELP}"
 echo
 echo
-make --no-print-directory -C "${KUBE_ROOT}" test-e2e-node FOCUS=${FOCUS:-} SKIP=${SKIP:-}
+make --no-print-directory -C "${KUBE_ROOT}" test-e2e-node FOCUS="${FOCUS:-}" SKIP="${SKIP:-}"