diff --git a/_tools/v3migration/v3migration.sh b/_tools/v3migration/v3migration.sh
index b8fc068..39f65e8 100644
--- a/_tools/v3migration/v3migration.sh
+++ b/_tools/v3migration/v3migration.sh
@@ -7,12 +7,12 @@ set -eu
 
 
 
-DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
-ROOT=$(cd ${DIR}/../.. && pwd)
+DIR="$(cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd)"
+ROOT=$(cd "${DIR}"/../.. && pwd)
 
 
 ## 1. refresh
-cd ${ROOT}
+cd "${ROOT}"
 
 /bin/rm -rf v3
 
@@ -23,22 +23,22 @@ cp -rp cpu disk docker host internal load mem net process winservices v3
 cp Makefile v3
 
 # build migartion tool
-go build -o v3/v3migration ${DIR}/v3migration.go
+go build -o v3/v3migration "${DIR}"/v3migration.go
 
 
-V3DIR=$(cd ${ROOT}/v3 && pwd)
-cd ${V3DIR}
+V3DIR=$(cd "${ROOT}"/v3 && pwd)
+cd "${V3DIR}"
 
 ## 3. mod
 go mod init
 
 ###  change import path
-find . -name "*.go" | xargs -I@ sed -i 's|"github.com/shirou/gopsutil/|"github.com/shirou/gopsutil/v3/|g' @
+find . -name "*.go" -print0 | xargs -0 -I@ sed -i 's|"github.com/shirou/gopsutil/|"github.com/shirou/gopsutil/v3/|g' @
 
 ############ Issues
 
 # #429 process.NetIOCounters is pointless on Linux
-./v3migration `pwd` 429
+./v3migration "$(pwd)" 429
 sed -i '/NetIOCounters/d' process/process.go
 sed -i "/github.com\/shirou\/gopsutil\/v3\/net/d" process/process_bsd.go
 
@@ -165,10 +165,7 @@ sed -i 's|PrioProcess|prioProcess|g' process/process_*.go
 sed -i 's|ClockTicks|clockTicks|g' process/process_*.go
 
 
-./v3migration `pwd` issueRemoveUnusedValue
+./v3migration "$(pwd)" issueRemoveUnusedValue
 
 
 ############ SHOULD BE FIXED BY HAND
-
-
-
diff --git a/coverall.sh b/coverall.sh
index 35aa298..f759a46 100644
--- a/coverall.sh
+++ b/coverall.sh
@@ -1,12 +1,12 @@
-#/bin/sh
+#!/bin/sh
 
 # see http://www.songmu.jp/riji/entry/2015-01-15-goveralls-multi-package.html
 
 set -e
 # cleanup
 cleanup() {
-  if [ $tmpprof != "" ] && [ -f $tmpprof ]; then
-    rm -f $tmpprof
+  if [ "$tmpprof" != "" ] && [ -f "$tmpprof" ]; then
+    rm -f "$tmpprof"
   fi
   exit
 }
@@ -14,13 +14,13 @@ trap cleanup INT QUIT TERM EXIT
 
 # メインの処理
 prof=${1:-".profile.cov"}
-echo "mode: count" > $prof
-gopath1=$(echo $GOPATH | cut -d: -f1)
+echo "mode: count" > "$prof"
+gopath1=$(echo "$GOPATH" | cut -d: -f1)
 for pkg in $(go list ./...); do
-  tmpprof=$gopath1/src/$pkg/profile.tmp
-  go test -covermode=count -coverprofile=$tmpprof $pkg
-  if [ -f $tmpprof ]; then
-    cat $tmpprof | tail -n +2 >> $prof
-    rm $tmpprof
+  tmpprof="$gopath1/src/$pkg/profile.tmp"
+  go test -covermode=count -coverprofile="$tmpprof" "$pkg"
+  if [ -f "$tmpprof" ]; then
+    tail -n +2 "$tmpprof" >> "$prof"
+    rm "$tmpprof"
   fi
 done
diff --git a/v2migration.sh b/v2migration.sh
index 978cc44..4b266f9 100644
--- a/v2migration.sh
+++ b/v2migration.sh
@@ -1,5 +1,6 @@
+#!/usr/bin/env bash
 # This script is a helper of migration to gopsutil v2 using gorename
-# 
+#
 # go get golang.org/x/tools/cmd/gorename
 
 IFS=$'\n'
@@ -12,7 +13,7 @@ IFS=$'\n'
 #   This scripts replace process.NetIOCounters() to IOCounters().
 #   So you need hand-fixing process.
 
-TARGETS=`cat <<EOF
+TARGETS=$(cat <<EOF
 CPUTimesStat -> TimesStat
 CPUInfoStat -> InfoStat
 CPUTimes -> Times
@@ -48,11 +49,12 @@ NetConnectionsPid -> ConnectionsPid
 Uid -> UID
 Id -> ID
 convertCpuTimes -> convertCPUTimes
-EOF`
+EOF
+)
 
 for T in $TARGETS
 do
-  echo $T
+  echo "$T"
   gofmt -w -r "$T" ./*.go
 done