diff --git a/Makefile b/Makefile
index 68ae4d2..9196b06 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,6 @@ lint: deps
 	golint -set_exit_status ./...
 
 cover: deps
-	go get github.com/axw/gocov/gocov
 	goveralls
 
 .PHONY: test deps lint cover
diff --git a/appveyor.yml b/appveyor.yml
new file mode 100644
index 0000000..8e7c5f8
--- /dev/null
+++ b/appveyor.yml
@@ -0,0 +1,9 @@
+version: "{build}"
+clone_folder: c:\gopath\src\github.com\Songmu\timeout
+environment:
+  GOPATH: c:\gopath
+build: false
+test_script:
+- go get -d -v -t ./...
+- go tool vet -all .
+- go test ./...
diff --git a/test/countup.pl b/testdata/countup.pl
similarity index 100%
rename from test/countup.pl
rename to testdata/countup.pl
diff --git a/test/dummy b/testdata/dummy
similarity index 100%
rename from test/dummy
rename to testdata/dummy
diff --git a/test/exit_with_23.pl b/testdata/exit_with_23.pl
similarity index 100%
rename from test/exit_with_23.pl
rename to testdata/exit_with_23.pl
diff --git a/test/ignore_sigterm.pl b/testdata/ignore_sigterm.pl
similarity index 100%
rename from test/ignore_sigterm.pl
rename to testdata/ignore_sigterm.pl
diff --git a/timeout.go b/timeout.go
index 23c5a3b..c9c0d47 100644
--- a/timeout.go
+++ b/timeout.go
@@ -8,7 +8,6 @@ import (
 	"os"
 	"os/exec"
 	"runtime"
-	"strconv"
 
 	"syscall"
 	"time"
@@ -104,7 +103,7 @@ func (tio *Timeout) signal() os.Signal {
 
 // Run is synchronous interface of executing command and returning information
 func (tio *Timeout) Run() (ExitStatus, string, string, error) {
-	cmd := tio.Cmd
+	cmd := tio.getCmd()
 	var outBuffer, errBuffer bytes.Buffer
 	cmd.Stdout = &outBuffer
 	cmd.Stderr = &errBuffer
@@ -120,7 +119,7 @@ func (tio *Timeout) Run() (ExitStatus, string, string, error) {
 
 // RunSimple executes command and only returns integer as exit code. It is mainly for go-timeout command
 func (tio *Timeout) RunSimple(preserveStatus bool) int {
-	cmd := tio.Cmd
+	cmd := tio.getCmd()
 
 	stdoutPipe, err := cmd.StdoutPipe()
 	if err != nil {
@@ -168,7 +167,7 @@ func getExitCodeFromErr(err error) int {
 
 // RunCommand is executing the command and handling timeout. This is primitive interface of Timeout
 func (tio *Timeout) RunCommand() (chan ExitStatus, error) {
-	cmd := tio.Cmd
+	cmd := tio.getCmd()
 
 	if err := cmd.Start(); err != nil {
 		switch {
@@ -199,7 +198,7 @@ func (tio *Timeout) RunCommand() (chan ExitStatus, error) {
 }
 
 func (tio *Timeout) handleTimeout() (ex ExitStatus) {
-	cmd := tio.Cmd
+	cmd := tio.getCmd()
 	exitChan := getExitChan(cmd)
 	select {
 	case exitCode := <-exitChan:
@@ -215,9 +214,8 @@ func (tio *Timeout) handleTimeout() (ex ExitStatus) {
 		select {
 		case ex.Code = <-exitChan:
 		case <-time.After(tio.KillAfter):
-			if runtime.GOOS == "windows" {
-				exec.Command("taskkill", "/F", "/T", "/PID", strconv.Itoa(cmd.Process.Pid)).Run()
-			}
+			tio.killall()
+			// just to make sure
 			cmd.Process.Kill()
 			ex.Code = exitKilled
 			ex.typ = exitTypeKilled
diff --git a/timeout_test.go b/timeout_test.go
index 7b6ec6e..1958a9b 100644
--- a/timeout_test.go
+++ b/timeout_test.go
@@ -72,7 +72,7 @@ func TestPreserveStatus(t *testing.T) {
 		t.Skipf("skip test on Windows")
 	}
 	tio := &Timeout{
-		Cmd:      exec.Command("perl", "test/exit_with_23.pl"),
+		Cmd:      exec.Command("perl", "testdata/exit_with_23.pl"),
 		Duration: 1 * time.Second,
 	}
 
@@ -84,7 +84,7 @@ func TestPreserveStatus(t *testing.T) {
 
 func TestKillAfter(t *testing.T) {
 	tio := &Timeout{
-		Cmd:       exec.Command("perl", "test/ignore_sigterm.pl"),
+		Cmd:       exec.Command("perl", "testdata/ignore_sigterm.pl"),
 		Signal:    syscall.SIGTERM,
 		Duration:  1 * time.Second,
 		KillAfter: 1 * time.Second,
@@ -98,7 +98,7 @@ func TestKillAfter(t *testing.T) {
 
 func TestKillAfterNotKilled(t *testing.T) {
 	tio := &Timeout{
-		Cmd:       exec.Command("perl", "test/ignore_sigterm.pl"),
+		Cmd:       exec.Command("perl", "testdata/ignore_sigterm.pl"),
 		Signal:    syscall.SIGTERM,
 		Duration:  1 * time.Second,
 		KillAfter: 5 * time.Second,
@@ -116,7 +116,7 @@ func TestCommandCannotBeInvoked(t *testing.T) {
 		t.Skipf("skip test on Windows")
 	}
 	tio := &Timeout{
-		Cmd:      exec.Command("test/dummy"),
+		Cmd:      exec.Command("testdata/dummy"),
 		Duration: 1 * time.Second,
 	}
 	exit := tio.RunSimple(false)
@@ -132,7 +132,7 @@ func TestCommandNotFound(t *testing.T) {
 		t.Skipf("skip test on Windows")
 	}
 	tio := &Timeout{
-		Cmd:      exec.Command("test/ignore_sigterm.pl-xxxxxxxxxxxxxxxxxxxxx"),
+		Cmd:      exec.Command("testdata/ignore_sigterm.pl-xxxxxxxxxxxxxxxxxxxxx"),
 		Duration: 1 * time.Second,
 	}
 	exit := tio.RunSimple(false)
diff --git a/timeout_unix.go b/timeout_unix.go
new file mode 100644
index 0000000..460c3c3
--- /dev/null
+++ b/timeout_unix.go
@@ -0,0 +1,19 @@
+// +build !windows
+
+package timeout
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+func (tio *Timeout) getCmd() *exec.Cmd {
+	if tio.Cmd.SysProcAttr == nil {
+		tio.Cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+	}
+	return tio.Cmd
+}
+
+func (tio *Timeout) killall() error {
+	return syscall.Kill(-tio.Cmd.Process.Pid, syscall.SIGKILL)
+}
diff --git a/timeout_windows.go b/timeout_windows.go
new file mode 100644
index 0000000..12b1a3c
--- /dev/null
+++ b/timeout_windows.go
@@ -0,0 +1,20 @@
+package timeout
+
+import (
+	"os/exec"
+	"strconv"
+	"syscall"
+)
+
+func (tio *Timeout) getCmd() *exec.Cmd {
+	if tio.Cmd.SysProcAttr == nil {
+		tio.Cmd.SysProcAttr = &syscall.SysProcAttr{
+			CreationFlags: syscall.CREATE_UNICODE_ENVIRONMENT | 0x00000200,
+		}
+	}
+	return tio.Cmd
+}
+
+func (tio *Timeout) killall() error {
+	return exec.Command("taskkill", "/F", "/T", "/PID", strconv.Itoa(tio.Cmd.Process.Pid)).Run()
+}