diff --git a/scripts/build/cross b/scripts/build/cross
index 919390dff3..51c22c3607 100755
--- a/scripts/build/cross
+++ b/scripts/build/cross
@@ -21,7 +21,7 @@ jobs=(
 # each container has access to two cores.
 group=${CROSS_GROUP-"all"}
 
-if [ "$group" == "all" ]; then
+if [ "$group" = "all" ]; then
 
     echo "Building binaries for all platforms"
     parallel ::: "${jobs[@]}"
diff --git a/scripts/gen/windows-resources b/scripts/gen/windows-resources
index 5fdc1b4ade..66d20f396a 100755
--- a/scripts/gen/windows-resources
+++ b/scripts/gen/windows-resources
@@ -14,7 +14,7 @@ RESOURCES=$SCRIPTDIR/../winresources
 TEMPDIR=$(mktemp -d)
 trap 'rm -rf $TEMPDIR' EXIT
 
-if [ "$(go env GOHOSTOS)" == "windows" ]; then
+if [ "$(go env GOHOSTOS)" = "windows" ]; then
 	WINDRES=windres
 else
 	# Cross compiling
@@ -22,7 +22,7 @@ else
 fi
 
 # Generate a Windows file version of the form major,minor,patch,build (with any part optional)
-VERSION_QUAD=$(echo -n "$VERSION" | sed -re 's/^([0-9.]*).*$/\1/' | tr . ,)
+VERSION_QUAD=$(printf "%s" "$VERSION" | sed -re 's/^([0-9.]*).*$/\1/' | tr . ,)
 
 # Pass version and commit information into the resource compiler
 defs=
@@ -30,7 +30,7 @@ defs=
 [ -n "$VERSION_QUAD" ] && defs+=( "-D DOCKER_VERSION_QUAD=$VERSION_QUAD")
 [ -n "$GITCOMMIT" ]    && defs+=( "-D DOCKER_COMMIT=\"$GITCOMMIT\"")
 
-function makeres {
+makeres() {
 	"$WINDRES" \
 		-i "$RESOURCES/$1" \
 		-o "$3" \
diff --git a/scripts/test/e2e/entry b/scripts/test/e2e/entry
index bbd1d3dd8f..98500fc070 100755
--- a/scripts/test/e2e/entry
+++ b/scripts/test/e2e/entry
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -eu -o pipefail
 
-if [[ -n "${REMOTE_DAEMON-}" ]]; then
+if [ -n "${REMOTE_DAEMON-}" ]; then
   # Run tests against a remote daemon.
   ./scripts/test/e2e/run fetch-images
   ./scripts/test/e2e/run test "${DOCKER_HOST-}"
diff --git a/scripts/test/e2e/load-image b/scripts/test/e2e/load-image
index 8aa56489ef..5245a211d1 100755
--- a/scripts/test/e2e/load-image
+++ b/scripts/test/e2e/load-image
@@ -8,16 +8,13 @@ alpine_dest=registry:5000/alpine:3.6
 busybox_src=busybox@sha256:3e8fa85ddfef1af9ca85a5cfb714148956984e02f00bec3f7f49d3925a91e0e7
 busybox_dest=registry:5000/busybox:1.27.2
 
-function fetch_tag_image {
-    local src=$1
-    local dest=$2
-    docker pull "$src"
-    docker tag "$src" "$dest"
+fetch_tag_image() {
+    docker pull "$1"
+    docker tag "$1" "$2"
 }
 
-function push_image {
-  local img=$1
-  docker push "$img"
+push_image() {
+  docker push "$1"
 }
 
 cmd=${1-}
diff --git a/scripts/test/e2e/run b/scripts/test/e2e/run
index 7f689b0ede..a9c5cc2683 100755
--- a/scripts/test/e2e/run
+++ b/scripts/test/e2e/run
@@ -2,24 +2,24 @@
 # Run integration tests against the latest docker-ce dind
 set -eu -o pipefail
 
-function container_ip {
+container_ip() {
     local cid=$1
     local network=$2
     docker inspect \
         -f "{{.NetworkSettings.Networks.${network}.IPAddress}}" "$cid"
 }
 
-function fetch_images {
+fetch_images() {
     ./scripts/test/e2e/load-image fetch-only
 }
 
-function setup {
+setup() {
     local project=$1
     local file=$2
 
     test "${DOCKERD_EXPERIMENTAL:-0}" -eq "1" && file="${file}:./e2e/compose-env.experimental.yaml"
 
-    if [[ "${TEST_CONNHELPER:-}" = "ssh" ]];then
+    if [ "${TEST_CONNHELPER:-}" = "ssh" ];then
         test ! -f "${HOME}/.ssh/id_rsa" && ssh-keygen -t rsa -C docker-e2e-dummy -N "" -f "${HOME}/.ssh/id_rsa" -q
         grep "^StrictHostKeyChecking no" "${HOME}/.ssh/config" > /dev/null 2>&1 || echo "StrictHostKeyChecking no" > "${HOME}/.ssh/config"
         TEST_CONNHELPER_SSH_ID_RSA_PUB=$(cat "${HOME}/.ssh/id_rsa.pub")
@@ -34,7 +34,7 @@ function setup {
 
     engine_ip="$(container_ip "${project}_engine_1" "$network")"
     engine_host="tcp://$engine_ip:2375"
-    if [[ "${TEST_CONNHELPER:-}" = "ssh" ]];then
+    if [ "${TEST_CONNHELPER:-}" = "ssh" ];then
         engine_host="ssh://penguin@${engine_ip}"
     fi
     (
@@ -46,18 +46,18 @@ function setup {
     echo "$engine_host"
 }
 
-function is_swarm_enabled {
+is_swarm_enabled() {
     docker info 2> /dev/null | grep -q 'Swarm: active'
 }
 
-function cleanup {
+cleanup() {
     local project=$1
     local network="${project}_default"
     docker network disconnect "$network" "$(hostname)"
     COMPOSE_PROJECT_NAME=$1 COMPOSE_FILE=$2 docker-compose down -v --rmi local >&2
 }
 
-function runtests {
+runtests() {
     local engine_host=$1
 
     # shellcheck disable=SC2086
@@ -94,7 +94,7 @@ case "$cmd" in
         ;;
     test)
         engine_host=${2-}
-        if [[ -z "${engine_host}" ]]; then
+        if [ -z "${engine_host}" ]; then
             echo "missing parameter docker engine host"
             echo "Usage: $0 test ENGINE_HOST"
             exit 3
diff --git a/scripts/test/e2e/wrapper b/scripts/test/e2e/wrapper
index 9e0342918c..5e2992506e 100755
--- a/scripts/test/e2e/wrapper
+++ b/scripts/test/e2e/wrapper
@@ -6,7 +6,7 @@ engine_host=$(./scripts/test/e2e/run setup)
 testexit=0
 
 test_cmd="test"
-if [[ -n "${TEST_DEBUG-}" ]]; then
+if [ -n "${TEST_DEBUG-}" ]; then
     test_cmd="shell"
 fi