diff --git a/script/setup/install-cni b/script/setup/install-cni
index 2bac9774f..3ae8803ac 100755
--- a/script/setup/install-cni
+++ b/script/setup/install-cni
@@ -21,18 +21,18 @@
 #
 set -eu -o pipefail
 
-CNI_COMMIT=$(grep containernetworking/plugins ${GOPATH}/src/github.com/containerd/containerd/vendor.conf | awk '{print $2}')
+CNI_COMMIT=$(grep containernetworking/plugins "$GOPATH"/src/github.com/containerd/containerd/vendor.conf | awk '{print $2}')
 CNI_DIR=/opt/cni
 CNI_CONFIG_DIR=/etc/cni/net.d
 
 go get -d github.com/containernetworking/plugins/...
-cd $GOPATH/src/github.com/containernetworking/plugins
+cd "$GOPATH"/src/github.com/containernetworking/plugins
 git checkout $CNI_COMMIT
 FASTBUILD=true ./build.sh
 mkdir -p $CNI_DIR
 cp -r ./bin $CNI_DIR
 mkdir -p $CNI_CONFIG_DIR
-bash -c 'cat >'$CNI_CONFIG_DIR'/10-containerd-net.conflist <<EOF
+cat > $CNI_CONFIG_DIR/10-containerd-net.conflist <<EOF
 {
   "cniVersion": "0.3.1",
   "name": "containerd-net",
@@ -57,4 +57,4 @@ bash -c 'cat >'$CNI_CONFIG_DIR'/10-containerd-net.conflist <<EOF
     }
   ]
 }
-EOF'
+EOF
diff --git a/script/setup/install-critools b/script/setup/install-critools
index 0870632ee..376291685 100755
--- a/script/setup/install-critools
+++ b/script/setup/install-critools
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
 #   Copyright The containerd Authors.
 
@@ -18,12 +18,12 @@
 # Builds and installs critools including critest and crictl
 # to /usr/local/bin.
 #
-set -eu -o pipefail
+set -eu
 
 go get -u github.com/onsi/ginkgo/ginkgo
 CRITEST_COMMIT=v1.16.1
 go get -d github.com/kubernetes-incubator/cri-tools/...
-cd $GOPATH/src/github.com/kubernetes-incubator/cri-tools
+cd "$GOPATH"/src/github.com/kubernetes-incubator/cri-tools
 git checkout $CRITEST_COMMIT
 make
 make install
diff --git a/script/setup/install-dev-tools b/script/setup/install-dev-tools
index 7f8de1e8a..e103f6ea6 100755
--- a/script/setup/install-dev-tools
+++ b/script/setup/install-dev-tools
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
 #   Copyright The containerd Authors.
 
@@ -18,14 +18,14 @@
 #
 # Install developer tools to $GOBIN (or $GOPATH/bin if unset)
 #
-set -eu -o pipefail
+set -eu
 
 go get -u github.com/stevvooe/protobuild
 go get -u github.com/golangci/golangci-lint/cmd/golangci-lint
 go get -u github.com/cpuguy83/go-md2man
 
 (
-	cd $GOPATH/src/github.com/golangci/golangci-lint/cmd/golangci-lint
+	cd "$GOPATH"/src/github.com/golangci/golangci-lint/cmd/golangci-lint
 	git checkout v1.18.0
 	go build -v && go install
 )
diff --git a/script/setup/install-protobuf b/script/setup/install-protobuf
index a002edfb6..fadc2e917 100755
--- a/script/setup/install-protobuf
+++ b/script/setup/install-protobuf
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
 #   Copyright The containerd Authors.
 
@@ -18,7 +18,7 @@
 #
 # Downloads and installs protobuf
 #
-set -eu -o pipefail
+set -eu
 
 PROTOBUF_VERSION=3.7.0
 GOARCH=$(go env GOARCH)
@@ -33,9 +33,9 @@ arm64)
 	;;
 
 amd64|386)
-	if [ $GOOS == "windows" ]; then
+	if [ "$GOOS" = windows ]; then
 		wget -O $PROTOBUF_DIR/protobuf "https://github.com/google/protobuf/releases/download/v$PROTOBUF_VERSION/protoc-$PROTOBUF_VERSION-win32.zip"
-	elif [ $GOOS == "linux" ]; then
+	elif [ "$GOOS" = linux ]; then
 		wget -O $PROTOBUF_DIR/protobuf "https://github.com/google/protobuf/releases/download/v$PROTOBUF_VERSION/protoc-$PROTOBUF_VERSION-linux-x86_64.zip"
 	fi
 	unzip $PROTOBUF_DIR/protobuf -d /usr/local
diff --git a/script/setup/install-runc b/script/setup/install-runc
index 3c382e399..2844d9965 100755
--- a/script/setup/install-runc
+++ b/script/setup/install-runc
@@ -21,9 +21,9 @@
 #
 set -eu -o pipefail
 
-RUNC_COMMIT=$(grep opencontainers/runc ${GOPATH}/src/github.com/containerd/containerd/vendor.conf | awk '{print $2}')
+RUNC_COMMIT=$(grep opencontainers/runc "$GOPATH"/src/github.com/containerd/containerd/vendor.conf | awk '{print $2}')
 
 go get -d github.com/opencontainers/runc
-cd $GOPATH/src/github.com/opencontainers/runc
+cd "$GOPATH"/src/github.com/opencontainers/runc
 git checkout $RUNC_COMMIT
-make BUILDTAGS="apparmor seccomp" runc install
+make BUILDTAGS='apparmor seccomp' runc install
diff --git a/script/setup/install-seccomp b/script/setup/install-seccomp
index d5569b78a..7cf4dae65 100755
--- a/script/setup/install-seccomp
+++ b/script/setup/install-seccomp
@@ -23,8 +23,8 @@ set -eu -o pipefail
 
 set -x
 
-export SECCOMP_VERSION="2.3.3"
-export SECCOMP_PATH="$(mktemp -d)"
+export SECCOMP_VERSION=2.3.3
+export SECCOMP_PATH=$(mktemp -d)
 curl -fsSL "https://github.com/seccomp/libseccomp/releases/download/v${SECCOMP_VERSION}/libseccomp-${SECCOMP_VERSION}.tar.gz" | tar -xzC "$SECCOMP_PATH" --strip-components=1
 (
 	cd "$SECCOMP_PATH"